Facebook, Inc. v. Duguid

Summary

To qualify as an “automatic telephone dialing system” under the Telephone Consumer Protection Act of 1991, a device must have the capacity either to store, or to produce, a telephone number using a random or sequential number generator.

Text

PRELIMINARY PRINT 
Volume 592 U. S. Part 2 
Pages 395–413 
OFFICIAL REPORTS 
OF 
THE SUPREME COURT 
April 1, 2021 
REBECCA A. WOMELDORF 
reporter of decisions 
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the bound volume is published. Users are requested to notify the Reporter 
of Decisions, Supreme Court of the United States, Washington, D.C. 20543, 
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OCTOBER TERM, 2020 395 
Syllabus 
FACEBOOK, INC. v. DUGUID et al. 
certiorari to the united states court of appeals for 
the ninth circuit 
No. 19–511. Argued December 8, 2020—Decided April 1, 2021 
The Telephone Consumer Protection Act of 1991 (TCPA) proscribes abu-
sive telemarketing practices by, among other things, restricting certain 
communications made with an “automatic telephone dialing system.” 
The TCPA defnes such “autodialers” as equipment with the capacity 
both “to store or produce telephone numbers to be called, using a ran-
dom or sequential number generator,” and to dial those numbers. 47 
U. S. C. § 227(a)(1). Petitioner Facebook, Inc., maintains a social media 
platform that, as a security feature, allows users to elect to receive text 
messages when someone attempts to log in to the user's account from a 
new device or browser. Facebook sent such texts to Noah Duguid, 
alerting him to login activity on a Facebook account linked to his tele-
phone number, but Duguid never created that account (or any account 
on Facebook). Duguid tried without success to stop the unwanted mes-
sages, and eventually brought a putative class action against Facebook. 
He alleged that Facebook violated the TCPA by maintaining a database 
that stored phone numbers and programming its equipment to send au-
tomated text messages. Facebook countered that the TCPA does not 
apply because the technology it used to text Duguid did not use a “ran-
dom or sequential number generator.” The Ninth Circuit disagreed, 
holding that § 227(a)(1) applies to a notifcation system like Facebook's 
that has the capacity to dial automatically stored numbers. 
Held: To qualify as an “automatic telephone dialing system” under the 
TCPA, a device must have the capacity either to store a telephone num-
ber using a random or sequential number generator, or to produce a 
telephone number using a random or sequential number generator. 
Pp. 402–409. 
(a) This case turns on whether the clause “using a random or 
sequential number generator” in § 227(a)(1)(A) modifes both of the two 
verbs that precede it (“store” and “produce”), as Facebook contends, or 
only the closest one (“produce”), as maintained by Duguid. The most 
natural reading of the text and other aspects of § 227(a)(1)(A) confrm 
Facebook's view. First, in an ordinary case, the “series-qualifer canon” 
instructs that a modifer at the end of a series of nouns or verbs applies 
to the entire series. Here, that canon indicates that the modifying 
phrase “using a random or sequential number generator” qualifes both

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396 FACEBOOK, INC. v. DUGUID 
Syllabus 
antecedent verbs, “store” and “produce.” Second, the modifying phrase 
immediately follows a concise, integrated clause (“store or produce tele-
phone numbers to be called”), which uses the word “or” to connect two 
verbs that share a common direct object (“telephone numbers to be 
called”). Given this structure, it would be odd to apply the modifer to 
just one part of the cohesive clause. Third, the comma in § 227(a)(1)(A) 
separating the modifying phrase from the antecedents suggests that the 
qualifer applies to all of the antecedents, instead of just the nearest 
one. Pp. 402–404. 
Duguid's insistence that a limiting clause should ordinarily be read as 
modifying only the phrase that it immediately follows (the so-called 
“rule of the last antecedent”) does not help his cause for two reasons. 
First, the Court has declined to apply that rule in the specifc context 
where, as here, the modifying clause appears after an integrated list. 
Jama v. Immigration and Customs Enforcement, 543 U. S. 335, 344, 
n. 4. Second, the last antecedent before the clause at issue in 
§ 227(a)(1)(A) is not “produce,” as Duguid argues, but rather “telephone 
numbers to be called.” Pp. 404. 
(b) The statutory context confrms that the TCPA's autodialer defni-
tion excludes equipment that does not use a random or sequential num-
ber generator. Congress found autodialer technology harmful because 
autodialers can dial emergency lines randomly or tie up all of the se-
quentially numbered phone lines at a single entity. Facebook's inter-
pretation of § 227(a)(1)(A) better matches the scope of the TCPA to 
these specifc concerns. Duguid's interpretation, on the other hand, 
would encompass any equipment that stores and dials telephone num-
bers. Pp. 405–406. 
(c) Duguid's other counterarguments do not overcome the clear com-
mands of the statute's text and broader context. First, he claims that 
his interpretation best accords with the “sense” of the text. It would 
make little sense however, to classify as autodialers all equipment with 
the capacity to store and dial telephone numbers, including virtually all 
modern cell phones. Second, Duguid invokes the “distributive canon,” 
which provides that a series of antecedents and consequents should be 
distributed to one another based on how they most naturally relate in 
context. But that canon is less suited here because there is only one 
consequent to match to two antecedents, and in any event, the modifying 
phrase naturally relates to both antecedents. Third, Duguid broadly 
construes the TCPA's privacy-protection goals. But despite Congress' 
general concern about intrusive telemarketing practices, Congress ulti-
mately chose a precise autodialer defnition. Finally, Duguid argues 
that a random or sequential number generator is a “senescent technol-

Cite as: 592 U. S. 395 (2021) 397 
Syllabus 
ogy,” i. e., one likely to become outdated quickly. That may or may not 
be the case, but either way, this Court cannot rewrite the TCPA to 
update it for modern technology. Congress' chosen defnition of an au-
todialer requires that the equipment in question must use a random or 
sequential number generator. That defnition excludes equipment like 
Facebook's login notifcation system, which does not use such technol-
ogy. Pp. 406–408. 
926 F. 3d 1146, reversed and remanded. 
Sotomayor, J., delivered the opinion of the Court, in which Roberts, 
C. J., and Thomas, Breyer, Kagan, Gorsuch, Kavanaugh, and 
Barrett, JJ., joined. Alito, J., fled an opinion concurring in the judg-
ment, post, p. 409. 
Paul D. Clement argued the cause for petitioner. With 
him on the briefs were Erin E. Murphy, Kasdin M. Mitchell, 
Lauren N. Beebe, Andrew B. Clubok, Roman Martinez, and 
Susan E. Engel. 
Jonathan Y . Ellis argued the cause for the United States 
as amicus curiae supporting petitioner. With him on the 
briefs were Acting Solicitor General Wall, Deputy Solicitor 
General Stewart, Sopan Joshi, Mark B. Stern, and Michael 
S. Raab. 
Bryan A. Garner argued the cause for respondents. With 
him on the brief were Sergei Lemberg, Karolyne H. C. Gar-
ner, Scott L. Nelson, and Allison M. Zieve.* 
*Briefs of amici curiae urging reversal were fled for the Chamber of 
Commerce of the United States of America et al. by Shay Dvoretzky and 
Thomas Pinder; for Healthcare Companies by Maxwell V. Pritt; for The 
Home Depot, Inc., by Keith Bradley, William P . Barnette, Ben W. Thorpe, 
and Benjamin Beaton; for the Life Insurance Direct Marketing Associa-
tion et al. by Ernesto R. Palomo and Brian I. Hays; for Midland Credit 
Management, Inc., by Zachary C. Schauf and Amy M. Gallegos; for Portfo-
lio Recovery Associates, LLC, by Misha Tseytlin; for the Professional As-
sociation for Customer Engagement et al. by Michele A. Shuster, Joshua 
O. Stevens, and Karl H. Koster; for Quicken Loans, LLC, by William M. 
Jay, Brooks R. Brown, and Andrew Kim; for the Retail Litigation Center, 
Inc., et al. by Joseph R. Palmore, Meredith C. Slawe, Michael W. McTigue, 
Jr., Deborah R. White, and Angelo I. Amador; for Salesforce.com, Inc., by 
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398 FACEBOOK, INC. v. DUGUID 
Opinion of the Court 
Justice Sotomayor delivered the opinion of the Court. 
The Telephone Consumer Protection Act of 1991 (TCPA) 
proscribes abusive telemarketing practices by, among other 
things, imposing restrictions on making calls with an “auto-
matic telephone dialing system.” As defned by the TCPA, 
an “automatic telephone dialing system” is a piece of equip-
Mark A. Perry; and for the Washington Legal Foundation by Corbin K. 
Barthold and Cory L. Andrews. 
Briefs of amici curiae urging affrmance were fled for the State of 
North Carolina et al. by Joshua H. Stein, Attorney General of North Caro-
lina, Ryan Y . Park, Solicitor General, Nicholas S. Brod, Assistant Solicitor 
General, by Curtis T. Hill, Jr., Attorney General of Indiana, Thomas M. 
Fisher, Solicitor General, Kian J. Hudson, Deputy Solicitor General, and 
Julia C. Payne, Deputy Attorney General, and by the Attorneys General 
and other offcials for their respective jurisdictions as follows: Clyde Snif-
fen, Jr., Acting Attorney General of Alaska, Mark Brnovich of Arizona, 
Leslie Rutledge of Arkansas, Xavier Becerra of California, Philip J. 
Weiser of Colorado, William Tong of Connecticut, Kathleen Jennings of 
Delaware, Karl A. Racine of the District of Columbia, Clare E. Connors 
of Hawaii, Lawrence G. Wasden of Idaho, Kwame Raoul of Illinois, 
Thomas J. Miller of Iowa, Derek Schmidt of Kansas, Daniel Cameron of 
Kentucky, Jeff Landry of Louisiana, Aaron M. Frey of Maine, Brian E. 
Frosh of Maryland, Maura Healey of Massachusetts, Dana Nessel of Mich-
igan, Keith Ellison of Minnesota, Lynn Fitch of Mississippi, Aaron D. 
Ford of Nevada, Gordon J. MacDonald of New Hampshire, Gurbir S. 
Grewal of New Jersey , Letitia James of New York, Wayne Stenehjem of 
North Dakota, Dave Yost of Ohio, Mike Hunter of Oklahoma, Ellen F. 
Rosenblum of Oregon, Josh Shapiro of Pennsylvania, Peter F. Neronha of 
Rhode Island, Herbert H. Slatery III of Tennessee, Thomas J. Donovan, 
Jr., of Vermont, Mark R. Herring of Virginia, Robert W. Ferguson of 
Washington, and Eric J. Wilson, Deputy Attorney General of Wisconsin; 
for the Electronic Privacy Information Center et al. by Alan Butler; for 
Main Street Alliance by John A. Yanchunis; for the National Consumer 
Law Center et al. by Tara Twomey; for John McCurley et al. by Abbas 
Kazerounian; for Dr. Henning Schulzrinne by Kris Skaar; and for 21 
Members of Congress by Keith J. Keogh. 
Briefs of amici curiae were fled for the Credit Union National Associa-
tion, Inc., by Julian R. Ellis, Jr., and Michael H. Pryor; and for “On-
Demand” Technology Platforms by Albert Giang , Michael D. Roth, and 
Anne M. Voigts. 
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Cite as: 592 U. S. 395 (2021) 399 
Opinion of the Court 
ment with the capacity both “to store or produce telephone 
numbers to be called, using a random or sequential number 
generator,” and to dial those numbers. 47 U. S. C. 
§ 227(a)(1). The question before the Court is whether that 
defnition encompasses equipment that can “store” and dial 
telephone numbers, even if the device does not “us[e] a ran-
dom or sequential number generator.” It does not. To 
qualify as an “automatic telephone dialing system,” a device 
must have the capacity either to store a telephone number 
using a random or sequential generator or to produce a 
telephone number using a random or sequential number 
generator. 
I 
A 
In 1991, Congress passed the TCPA to address “the prolif-
eration of intrusive, nuisance calls” to consumers and busi-
nesses from telemarketers. § 2, ¶¶1, 6, 105 Stat. 2394, note 
following 47 U. S. C. § 227. Advances in automated technol-
ogy made it feasible for companies to execute large-scale 
telemarketing campaigns at a fraction of the prior cost, dra-
matically increasing customer contacts. Infamously, the 
development of “robocall” technology allowed companies to 
make calls using artifcial or prerecorded voices, obviating 
the need for live human callers altogether. 
This case concerns “automatic telephone dialing systems” 
(hereinafter autodialers), which revolutionized telemarket-
ing by allowing companies to dial random or sequential 
blocks of telephone numbers automatically. Congress found 
autodialer technology to be uniquely harmful. It threatened 
public safety by “seizing the telephone lines of public emer-
gency services, dangerously preventing those lines from 
being utilized to receive calls from those needing emergency 
services.” H. R. Rep. No. 102–317, p. 24 (1991). Indeed, 
due to the sequential manner in which they could generate 
numbers, autodialers could simultaneously tie up all the lines 
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400 FACEBOOK, INC. v. DUGUID 
Opinion of the Court 
of any business with sequentially numbered phone lines. 
Nor were individual consumers spared: Autodialers could 
reach cell phones, pagers, and unlisted numbers, inconven-
iencing consumers and imposing unwanted fees.
1 Ibid. 
Against this technological backdrop, Congress made it un-
lawful to make certain calls “using any automatic telephone 
dialing system” to “emergency telephone line[s],” to “guest 
room[s] or patient room[s] of a hospital,” or “to any telephone 
number assigned to a paging service [or] cellular telephone 
service” without the “prior express consent of the called 
party.” 47 U. S. C. § 227(b)(1)(A).
2 The TCPA creates a 
private right of action for persons to sue to enjoin unlawful 
uses of autodialers and to recover up to $1,500 per viola-
tion or three times the plaintiffs' actual monetary losses. 
§ 227(b)(3). 
B 
Petitioner Facebook, Inc., maintains a social media plat-
form with an optional security feature that sends users 
“login notifcation” text messages when an attempt is made 
to access their Facebook account from an unknown device or 
browser. If necessary, the user can then log into Facebook 
and take action to secure the account. To opt in to this serv-
ice, the user must provide and verify a cell phone number to 
which Facebook can send messages. 
In 2014, respondent Noah Duguid received several login-
notifcation text messages from Facebook, alerting him that 
someone had attempted to access the Facebook account asso-
1 At the time Congress enacted the TCPA, most cellular providers 
charged users not only for outgoing calls but also for incoming calls. See 
In re Rules and Regulations Implementing Telephone Consumer Protec-
tion Act of 1991, 18 FCC Rcd. 14014, 14115 (2003). 
2 Neither party disputes that the TCPA's prohibition also extends to 
sending unsolicited text messages. See Campbell-Ewald Co. v. Gomez, 
577 U. S. 153, 156 (2016). We therefore assume that it does without con-
sidering or resolving that issue. 
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Cite as: 592 U. S. 395 (2021) 401 
Opinion of the Court 
ciated with his phone number from an unknown browser. 
But Duguid has never had a Facebook account and never 
gave Facebook his phone number. 3 Unable to stop the noti-
fcations, Duguid brought a putative class action against 
Facebook. He alleged that Facebook violated the TCPA by 
maintaining a database that stored phone numbers and pro-
gramming its equipment to send automated text messages to 
those numbers each time the associated account was accessed 
by an unrecognized device or web browser. 
Facebook moved to dismiss the suit, arguing primarily 
that Duguid failed to allege that Facebook used an autodialer 
because he did not claim Facebook sent text messages to 
numbers that were randomly or sequentially generated. 
Rather, Facebook argued, Duguid alleged that Facebook sent 
targeted, individualized texts to numbers linked to specifc 
accounts. The U. S. District Court for the Northern Dis-
trict of California agreed and dismissed Duguid's amended 
complaint with prejudice. 2017 WL 635117, *4–*5 (Feb. 16, 
2017). 
The United States Court of Appeals for the Ninth Circuit 
reversed. As relevant here, the Ninth Circuit held that Du-
guid had stated a claim under the TCPA by alleging that 
Facebook's notifcation system automatically dialed stored 
numbers. An autodialer, the Court of Appeals held, need 
not be able to use a random or sequential generator to store 
numbers; it need only have the capacity to “ `store numbers 
to be called' ” and “ `to dial such numbers automatically.' ” 
926 F. 3d 1146, 1151 (2019) (quoting Marks v. Crunch San 
Diego, LLC , 904 F. 3d 1041, 1053 (CA9 2018)). 
We granted certiorari to resolve a confict among the 
Courts of Appeals regarding whether an autodialer must 
have the capacity to generate random or sequential phone 
3 As Facebook explains, it is possible that Duguid was assigned a recy-
cled cell phone number that previously belonged to a Facebook user who 
opted to receive login notifcations. 
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402 FACEBOOK, INC. v. DUGUID 
Opinion of the Court 
numbers.4 591 U. S. ––– (2020). We now reverse the Ninth 
Circuit's judgment. 
II 
Section 227(a)(1) defnes an autodialer as: 
“equipment which has the capacity— 
“(A) to store or produce telephone numbers to be 
called, using a random or sequential number generator; 
and 
“(B) to dial such numbers.” 
Facebook argues the clause “using a random or sequential 
number generator” modifes both verbs that precede it 
(“store” and “produce”), while Duguid contends it modifes 
only the closest one (“produce”). We conclude that the 
clause modifes both, specifying how the equipment must 
either “store” or “produce” telephone numbers. Because 
Facebook's notifcation system neither stores nor produces 
numbers “using a random or sequential number generator,” 
it is not an autodialer. 
A 
We begin with the text. Congress defned an autodialer 
in terms of what it must do (“store or produce telephone 
numbers to be called”) and how it must do it (“using a ran-
dom or sequential number generator”). The defnition uses 
a familiar structure: a list of verbs followed by a modifying 
clause. Under conventional rules of grammar, “[w]hen there 
is a straightforward, parallel construction that involves all 
nouns or verbs in a series,” a modifer at the end of the list 
“normally applies to the entire series.” A. Scalia & B. Gar-
ner, Reading Law: The Interpretation of Legal Texts 147 
4 Compare 926 F. 3d 1146, 1151–1152 (CA9 2019); Duran v. La Boom 
Disco, Inc., 955 F. 3d 279, 290 (CA2 2020); and Allan v. Pennsylvania 
Higher Educ. Assistance Agency , 968 F. 3d 567, 579–580 (CA6 2020), with 
Gadelhak v. AT&T Servs., Inc., 950 F. 3d 458, 468 (CA7 2020) (Barrett, J., for 
the court); Glasser v. Hilton Grand Vacations Co., 948 F. 3d 1301, 1306–1307 
(CA11 2020); and Dominguez v. Yahoo, Inc., 894 F. 3d 116, 119 (CA3 2018). 
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Cite as: 592 U. S. 395 (2021) 403 
Opinion of the Court 
(2012) (Scalia & Garner) (quotation modifed). The Court 
often applies this interpretative rule, usually referred to as 
the “series-qualifer canon.” See Paroline v. United States, 
572 U. S. 434, 447 (2014) (citing Porto Rico Railway, Light & 
Power Co. v. Mor, 253 U. S. 345, 348 (1920)); see also United 
States v. Bass, 404 U. S. 336, 339–340 (1971). This canon 
generally refects the most natural reading of a sentence. 
Imagine if a teacher announced that “students must not com-
plete or check any homework to be turned in for a grade, 
using online homework-help websites.” It would be strange 
to read that rule as prohibiting students from completing 
homework altogether, with or without online support. 
Here, the series-qualifer canon recommends qualifying 
both antecedent verbs, “store” and “produce,” with the 
phrase “using a random or sequential number generator.” 
That recommendation produces the most natural construc-
tion, as confrmed by other aspects of § 227(a)(1)(A)'s text. 
To begin, the modifer at issue immediately follows a con-
cise, integrated clause: “store or produce telephone numbers 
to be called.” See Cyan, Inc. v. Beaver County Employees 
Retirement Fund, 583 U. S. 416, 440 (2018). The clause 
“hangs together as a unifed whole,” ibid. using the word 
“or” to connect two verbs that share a common direct 
object, “telephone numbers to be called.” It would be odd to 
apply the modifer (“using a random or sequential number 
generator”) to only a portion of this cohesive preceding 
clause. 
This interpretation of § 227(a)(1)(A) also “heed[s] the com-
mands of its punctuation.” United States Nat. Bank of Ore. 
v. Independent Ins. Agents of America, Inc., 508 U. S. 439, 
454 (1993). Recall that the phrase “using a random or se-
quential number generator” follows a comma placed after the 
phrase “store or produce telephone numbers to be called.” 
As several leading treatises explain, “ `[a] qualifying phrase 
separated from antecedents by a comma is evidence that the 
qualifer is supposed to apply to all the antecedents instead 
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404 FACEBOOK, INC. v. DUGUID 
Opinion of the Court 
of only to the immediately preceding one.' ” W. Eskridge, 
Interpreting Law: A Primer on How To Read Statutes and 
the Constitution 67–68 (2016); see also 2A N. Singer & 
S. Singer, Sutherland Statutes and Statutory Construction 
§ 47:33, pp. 499–500 (rev. 7th ed. 2014); Scalia & Garner 161– 
162. The comma in § 227(a)(1)(A) thus further suggests that 
Congress intended the phrase “using a random or sequential 
number generator” to apply equally to both preceding 
elements. 
Contrary to Duguid's view, this interpretation does not 
confict with the so-called “rule of the last antecedent.” 
Under that rule, “a limiting clause or phrase . . . should ordi-
narily be read as modifying only the noun or phrase that it 
immediately follows.” Barnhart v. Thomas, 540 U. S. 20, 26 
(2003); see also Lockhart v. United States, 577 U. S. 347, 351 
(2016). The rule of the last antecedent is context dependent. 
This Court has declined to apply the rule where, like here, 
the modifying clause appears after an integrated list. See 
Jama v. Immigration and Customs Enforcement, 543 U. S. 
335, 344, n. 4 (2005) (collecting cases). Moreover, even if the 
rule of the last antecedent were relevant here, it would pro-
vide no help to Duguid. The last antecedent before “using 
a random or sequential number generator” is not “produce,” 
as Duguid needs it to be, but rather “telephone numbers to 
be called.” There is “no grammatical basis,” Cyan, 583 
U. S., at 441, for arbitrarily stretching the modifer back to 
include “produce,” but not so far back as to include “store.” 
In sum, Congress' defnition of an autodialer requires that 
in all cases, whether storing or producing numbers to be 
called, the equipment in question must use a random or se-
quential number generator. This defnition excludes equip-
ment like Facebook's login notifcation system, which does 
not use such technology.
5 
5 Justice Alito notes that he “agree[s] with much of the Court's 
analysis,” as well as its ultimate conclusion about the interpretive question 
before us, yet he concurs in the judgment only. Post, at 409–410. His 
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Opinion of the Court 
B 
The statutory context confrms that the autodialer defni-
tion excludes equipment that does not “us[e] a random or 
sequential number generator.” 47 U. S. C. § 227(a)(1)(A). 
Consider the TCPA's restrictions on the use of autodialers. 
As previously noted, § 227(b)(1) makes it unlawful to use an 
autodialer to call certain “emergency telephone line[s]” and 
lines “for which the called party is charged for the call.” 
§ 227(b)(1)(A). It also makes it unlawful to use an autodialer 
“in such a way that two or more telephone lines of a multi-
line business are engaged simultaneously.” § 227(b)(1)(D). 
These prohibitions target a unique type of telemarketing 
equipment that risks dialing emergency lines randomly or 
tying up all the sequentially numbered lines at a single 
entity. 
Expanding the defnition of an autodialer to encompass any 
equipment that merely stores and dials telephone numbers 
would take a chainsaw to these nuanced problems when Con-
gress meant to use a scalpel. Duguid's interpretation of an 
autodialer would capture virtually all modern cell phones, 
apprehension appears to stem from what he sees as the Court's “heavy 
reliance” on the series-qualifer canon. Id., at 410. Such canons, he ar-
gues, are “not infexible rules.” Post, at 413. On that point, we agree: 
Linguistic canons are tools of statutory interpretation whose usefulness 
depends on the particular statutory text and context at issue. That may 
be all Justice Alito seeks to prove with his discussion and list of “sen-
tences that clearly go against the canon,” post, at 411. (That the gram-
matical structure of every example he provides is materially dissimilar 
from that of the clause at issue in this case proves the point.) But to the 
extent that he suggests that such canons have no role to play in statutory 
interpretation, or that resolving diffcult interpretive questions is a simple 
matter of applying the “common understanding” of those “familiar with 
the English language,” post, at 411–412, we disagree. Diffcult ambigu-
ities in statutory text will inevitably arise, despite the best efforts of legis-
lators writing in “English prose,” post, at 413. Courts should approach 
these interpretive problems methodically, using traditional tools of statu-
tory interpretation, in order to confrm their assumptions about the “com-
mon understanding” of words. 
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406 FACEBOOK, INC. v. DUGUID 
Opinion of the Court 
which have the capacity to “store . . . telephone numbers to 
be called” and “dial such numbers.” § 227(a)(1). The 
TCPA's liability provisions, then, could affect ordinary cell 
phone owners in the course of commonplace usage, such as 
speed dialing or sending automated text message responses. 
See § 227(b)(3) (authorizing a $500 fne per violation, in-
creased to $1,500 if the sender acted “willfully” or 
“knowingly”).
6 
III 
Duguid's counterarguments cannot overcome the clear 
commands of § 227(a)(1)(A)'s text and the statutory context. 
The crux of Duguid's argument is that the autodialer defni-
tion calls for a construction that accords with the “sense” of 
the text. Brief for Respondents 11, and n. 3. It makes the 
most “sense,” Duguid insists, to apply the phrase “using a 
random or sequential number generator” to modify only 
“produce,” which, unlike the verb “store,” is closely con-
nected to the noun “generator.” Dictionary defnitions of 
“generator,” for instance, regularly include the word 
“produce,” which carries a very different meaning than 
“store.” Duguid also claims that, at the time of the TCPA's 
enactment, the technical meaning of a “random number gen-
erator” invoked ways of producing numbers, not means of 
storing them. 
Perhaps Duguid's interpretive approach would have some 
appeal if applying the traditional tools of interpretation led 
to a “linguistically impossible” or contextually implausible 
6 Duguid contends that ordinary cell phones are not autodialers under 
his interpretation because they cannot dial phone numbers automatically 
and instead rely on human intervention. But all devices require some 
human intervention, whether it takes the form of programming a cell 
phone to respond automatically to texts received while in “do not disturb” 
mode or commanding a computer program to produce and dial phone num-
bers at random. We decline to interpret the TCPA as requiring such 
a diffcult line-drawing exercise around how much automation is too 
much. 
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Cite as: 592 U. S. 395 (2021) 407 
Opinion of the Court 
outcome. Encino Motorcars, LLC v. Navarro, 584 U. S. 
–––, ––– (2018); see also Advocate Health Care Network v. 
Stapleton, 581 U. S. 468, 480 (2017) (noting that a “sense of 
inconceivability” might “urg[e] readers to discard usual rules 
of interpreting text”). Duguid makes a valiant effort to 
prove as much, but ultimately comes up short. It is true 
that, as a matter of ordinary parlance, it is odd to say that a 
piece of equipment “stores” numbers using a random number 
“generator.” But it is less odd as a technical matter. In-
deed, as early as 1988, the U. S. Patent and Trademark Offce 
issued patents for devices that used a random number gener-
ator to store numbers to be called later (as opposed to using 
a number generator for immediate dialing).
7 Brief for Pro-
fessional Association for Customer Engagement et al. as 
Amici Curiae 15–21. At any rate, Duguid's interpretation 
is contrary to the ordinary reading of the text and, by classi-
fying almost all modern cell phones as autodialers, would 
produce an outcome that makes even less sense. 
Duguid's reliance on the distributive canon fails for similar 
reasons. That canon provides that “[w]here a sentence con-
tains several antecedents and several consequents,” courts 
should “read them distributively and apply the words to the 
subjects which, by context, they seem most properly to re-
late.” 2A Singer, Sutherland Statutes and Statutory Con-
7 Duguid argues that such a device would necessarily “produce” numbers 
using the same generator technology, meaning “store or” in § 227(a)(1)(A) 
is superfuous. “It is no superfuity,” however, for Congress to include 
both functions in the autodialer defnition so as to clarify the domain of 
prohibited devices. BFP v. Resolution Trust Corporation, 511 U. S. 531, 
544, n. 7 (1994). For instance, an autodialer might use a random number 
generator to determine the order in which to pick phone numbers from a 
preproduced list. It would then store those numbers to be dialed at a 
later time. See Brief for Professional Association for Customer Engage-
ment et al. as Amici Curiae 19. In any event, even if the storing and 
producing functions often merge, Congress may have “employed a belt 
and suspenders approach” in writing the statute. Atlantic Richfeld Co. 
v. Christian, 590 U. S. –––, –––, n. 5 (2020). 
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408 FACEBOOK, INC. v. DUGUID 
Opinion of the Court 
struction § 47:26, at 448. Set aside for a moment that the 
canon's relevance is highly questionable given there are two 
antecedents (store and produce) but only one consequent 
modifer (using a random or sequential number generator). 
See Encino Motorcars, 584 U. S., at ––– (“[T]he distributive 
canon has the most force when the statute allows for one-to-
one matching”). As just explained, the consequent “using a 
random or sequential number generator” properly relates to 
both antecedents. 
Duguid next turns to legislative purpose, but he merely 
gestures at Congress' “broad privacy-protection goals.” 
Brief for Respondents 28 (emphasizing that Congress prohib-
ited calls made using an autodialer without “ `prior express 
consent of the called party' ” (quoting 47 U. S. C. § 227(b) 
(1)(A))). That Congress was broadly concerned about intru-
sive telemarketing practices, however, does not mean it 
adopted a broad autodialer defnition. Congress expressly 
found that the use of random or sequential number generator 
technology caused unique problems for business, emergency, 
and cellular lines. See supra, at 399–400. Unsurprisingly, 
then, the autodialer defnition Congress employed includes 
only devices that use such technology, and the autodialer pro-
hibitions target calls made to such lines. See § 227(b)(1)(A).
8 
The narrow statutory design, therefore, does not support 
Duguid's broad interpretation. 
Duguid last warns that accepting Facebook's interpreta-
tion will “unleash” a “torrent of robocalls.” Brief for Re-
spondents 38 (quotation modifed). As Duguid sees it, the 
thrust of congressional action since the TCPA's enactment 
has been to restrict nuisance calls. Because technology 
“adapt[s] to change,” Duguid argues, the TCPA must be 
8 By contrast, Congress did impose broader prohibitions elsewhere in 
the TCPA. See, e. g., 47 U. S. C. §§ 227(b)(1)(A) and (B) (prohibiting “arti-
fcial or prerecorded voice” calls, irrespective of the type of technology 
used). 
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Cite as: 592 U. S. 395 (2021) 409 
Alito, J., concurring in judgment 
treated as an “ `agile tool.' ” Id., at 38, 41. To this end, Du-
guid asks this Court to focus not on whether a device has 
the “senescent technology,” id., at 41, of random or sequen-
tial number generation but instead on whether it has the 
“capacity to dial numbers without human intervention,” id., 
at 39 (internal quotation marks omitted). 
To begin with, Duguid greatly overstates the effects of 
accepting Facebook's interpretation. The statute sepa -
rately prohibits calls using “an artifcial or prerecorded 
voice” to various types of phone lines, including home phones 
and cell phones, unless an exception applies. See 47 U. S. C. 
§§ 227(b)(1)(A) and (B). Our decision does not affect that 
prohibition. In any event, Duguid's quarrel is with Con-
gress, which did not defne an autodialer as malleably as he 
would have liked. “Senescent” as a number generator (and 
perhaps the TCPA itself ) may be, that is no justifcation 
for eschewing the best reading of § 227(a)(1)(A). This Court 
must interpret what Congress wrote, which is that “using 
a random or sequential number generator” modifes both 
“store” and “produce.” 
* * * 
We hold that a necessary feature of an autodialer under 
§ 227(a)(1)(A) is the capacity to use a random or sequential 
number generator to either store or produce phone numbers 
to be called. The judgment of the Court of Appeals is re-
versed, and the case is remanded for further proceedings 
consistent with this opinion. 
It is so ordered. 
Justice Alito, concurring in the judgment. 
I agree with the Court that an “automatic telephone dial-
ing system,” as defned in the Telephone Consumer Protec-
tion Act of 1991, must have the capacity to “store . . . tele-
phone numbers” by “using a random or sequential number 
generator.” 47 U. S. C. § 227(a)(1)(A). I also agree with 
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410 FACEBOOK, INC. v. DUGUID 
Alito, J., concurring in judgment 
much of the Court's analysis and the analysis in several 
Court of Appeals decisions on this question. See Gadelhak 
v. AT&T Servs., Inc., 950 F. 3d 458, 463–468 (CA7 2020); 
Glasser v. Hilton Grand Vacations Co., 948 F. 3d 1301, 1306– 
1312 (CA11 2020). 
I write separately to address the Court's heavy reliance 
on one of the canons of interpretation that have come to play 
a prominent role in our statutory interpretation cases. Cat-
aloged in a treatise written by our former colleague Antonin 
Scalia and Bryan A. Garner, counsel for respondents in this 
case, these canons are useful tools, but it is important to keep 
their limitations in mind. This may be especially true with 
respect to the particular canon at issue here, the “series-
qualifer” canon. 
According to the majority's recitation of this canon, 
“ `[w]hen there is a straightforward, parallel construction 
that involves all nouns or verbs in a series,' a modifer at 
the end of the list `normally applies to the entire series.' ” 
Ante, at 402 (quoting A. Scalia & B. Garner, Reading Law: 
The Interpretation of Legal Texts 147 (2012) (Reading 
Law)).* 
The Court refers to this canon as a “rul[e] of grammar.” 
Ante, at 402. Yet the Scalia-Garner treatise makes it clear 
that interpretive canons “are not `rules' of interpretation in 
any strict sense but presumptions about what an intelli-
gently produced text conveys.” Reading Law 51. (Even 
grammar, according to Mr. Garner, is ordinarily just “an at-
tempt to describe the English language as it is actually 
used.” B. Garner, The Chicago Guide to Grammar, Usage, 
and Punctuation 1 (2016)). And Reading Law goes out of 
*As set out in Reading Law 147, this canon also applies when the mod-
ifer precedes the series of verbs or nouns. 
Some scholars have claimed that “nobody proposed [the series-qualifer] 
canon until Justice Scalia pioneered it” in Reading Law. Baude & Sachs, 
The Law of Interpretation, 130 Harv. L. Rev. 1079, 1125 (2017) (internal 
quotation marks omitted; emphasis deleted). 
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Cite as: 592 U. S. 395 (2021) 411 
Alito, J., concurring in judgment 
its way to emphasize the limitations of the series-qualifer 
canon, warning: 
“Perhaps more than most of the other canons, [the 
series-qualifer canon] is highly sensitive to context. 
Often the sense of the matter prevails: He went forth 
and wept bitterly does not suggest that he went forth 
bitterly.” Reading Law 150. 
The italicized sentence—an English translation of a sen-
tence in the New Testament, Matthew 26:75—is not only 
grammatical; it is perfectly clear. No one familiar with the 
English language would fail to understand it—even though 
its meaning is contrary to the one suggested by the series-
qualifer canon. 
The Court writes that the series-qualifer canon “generally 
refects the most natural reading of a sentence,” ante, at 403, 
and maybe that is so. But cf. Lockhart v. United States, 577 
U. S. 347, 351 (2016) (relying on “the basic intuition that 
when a modifer appears at the end of a list, it is easier to 
apply that modifer only to the item directly before it”). But 
it is very easy to think of sentences that clearly go against 
the canon: 
“At the Super Bowl party, she ate, drank, and cheered 
raucously.” 
“On Saturday, he relaxes and exercises vigorously.” 
“When his owner comes home, the dog wags his tail and 
barks loudly.” 
“It is illegal to hunt rhinos and giraffes with necks 
longer than three feet.” 
“She likes to swim and run wearing track spikes.” 
In support of its treatment of the series-qualifer canon, 
the Court offers this example of a sentence in which the 
natural reading corresponds with the interpretation sug-
gested by the canon: “[S]tudents must not complete or check 
any homework to be turned in for a grade, using online 
homework-help websites.” Ante, at 403. I certainly agree 
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412 FACEBOOK, INC. v. DUGUID 
Alito, J., concurring in judgment 
that the adverbial phrase in this sentence (“using online 
homework-help websites”) modifes both of the verbs it fol-
lows (“complete” and “check”) and not just the latter. But 
that understanding has little to do with syntax and every-
thing to do with our common understanding that teachers do 
not want to prohibit students from doing homework. We 
can see this point clearly if we retain the same syntax but 
replace the verb “complete” with any number of other verbs 
that describe something a teacher is not likely to want stu-
dents to do, say, “ignore,” “overlook,” “discard,” “lose,” “ne-
glect,” “forget,” “destroy,” “throw away,” or “incinerate” 
their homework. The concept of “using online homework-
help websites” to do any of those things would be nonsensi-
cal, and no reader would interpret the sentence to have that 
meaning—even though that is what the series-qualifer 
canon suggests. 
The strength and validity of an interpretive canon is an 
empirical question, and perhaps someday it will be possible 
to evaluate these canons by conducting what is called a cor-
pus linguistics analysis, that is, an analysis of how particular 
combinations of words are used in a vast database of English 
prose. See generally Lee & Mouritsen, Judging Ordinary 
Meaning, 127 Yale L. J. 788 (2018). If the series-qualifer 
canon were analyzed in this way, I suspect we would fnd 
that series qualifers sometimes modify all the nouns or 
verbs in a list and sometimes modify just the last noun or 
verb. It would be interesting to see if the percentage of 
sentences in the frst category is high enough to justify the 
canon. But no matter how the sentences with the relevant 
structure broke down, it would be surprising if “the sense of 
the matter” did not readily reveal the meaning in the great 
majority of cases. Reading Law 150. 
That is just my guess. Empirical evidence might prove 
me wrong, but that is not what matters. The important 
point is that interpretive canons attempt to identify the way 
in which “a reasonable reader, fully competent in the lan-
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Cite as: 592 U. S. 395 (2021) 413 
Alito, J., concurring in judgment 
guage, would have understood the text at the time it was 
issued.” Id., at 33. To the extent that interpretive canons 
accurately describe how the English language is generally 
used, they are useful tools. But they are not infexible rules. 
Appellate judges spend virtually every working hour 
speaking, listening to, reading, or writing English prose. 
Statutes are written in English prose, and interpretation is 
not a technical exercise to be carried out by mechanically 
applying a set of arcane rules. Canons of interpretation can 
help in fguring out the meaning of troublesome statutory 
language, but if they are treated like rigid rules, they can 
lead us astray. When this Court describes canons as rules 
or quotes canons while omitting their caveats and limita-
tions, we only encourage the lower courts to relegate statu-
tory interpretation to a series of if-then computations. No 
reasonable reader interprets texts that way. 
For these reasons, I respectfully concur in the judgment. 
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Retrieval chunks

• #1

  PRELIMINARY PRINT Volume 592 U. S. Part 2 Pages 395–413 OFFICIAL REPORTS OF THE SUPREME COURT April 1, 2021 REBECCA A. WOMELDORF reporter of decisions Page Proof Pending Publication NOTICE: This preliminary print is subject to formal revision before the bound volume is published. Users are requested to noti…

• #2

  (a) This case turns on whether the clause “using a random or sequential number generator” in § 227(a)(1)(A) modifes both of the two verbs that precede it (“store” and “produce”), as Facebook contends, or only the closest one (“produce”), as maintained by Duguid. The most natural reading of the text and other aspec…

• #3

  (c) Duguid's other counterarguments do not overcome the clear com- mands of the statute's text and broader context. First, he claims that his interpretation best accords with the “sense” of the text. It would make little sense however, to classify as autodialers all equipment with the capacity to store and dial te…

• #4

  Commerce of the United States of America et al. by Shay Dvoretzky and Thomas Pinder; for Healthcare Companies by Maxwell V. Pritt; for The Home Depot, Inc., by Keith Bradley, William P . Barnette, Ben W. Thorpe, and Benjamin Beaton; for the Life Insurance Direct Marketing Associa- tion et al. by Ernesto R. Palomo …

• #5

  igan, Keith Ellison of Minnesota, Lynn Fitch of Mississippi, Aaron D. Ford of Nevada, Gordon J. MacDonald of New Hampshire, Gurbir S. Grewal of New Jersey , Letitia James of New York, Wayne Stenehjem of North Dakota, Dave Yost of Ohio, Mike Hunter of Oklahoma, Ellen F. Rosenblum of Oregon, Josh Shapiro of Pennsylv…

• #6

  (hereinafter autodialers), which revolutionized telemarket- ing by allowing companies to dial random or sequential blocks of telephone numbers automatically. Congress found autodialer technology to be uniquely harmful. It threatened public safety by “seizing the telephone lines of public emer- gency services, dan…

• #7

  2 Neither party disputes that the TCPA's prohibition also extends to sending unsolicited text messages. See Campbell-Ewald Co. v. Gomez, 577 U. S. 153, 156 (2016). We therefore assume that it does without con- sidering or resolving that issue. Page Proof Pending Publication Cite as: 592 U. S. 395 (2021) 401 Opin…

• #8

  Section 227(a)(1) defnes an autodialer as: “equipment which has the capacity— “(A) to store or produce telephone numbers to be called, using a random or sequential number generator; and “(B) to dial such numbers.” Facebook argues the clause “using a random or sequential number generator” modifes both verbs that…

• #9

  homework altogether, with or without online support. Here, the series-qualifer canon recommends qualifying both antecedent verbs, “store” and “produce,” with the phrase “using a random or sequential number generator.” That recommendation produces the most natural construc- tion, as confrmed by other aspects of § …

• #10

  the modifying clause appears after an integrated list. See Jama v. Immigration and Customs Enforcement, 543 U. S. 335, 344, n. 4 (2005) (collecting cases). Moreover, even if the rule of the last antecedent were relevant here, it would pro- vide no help to Duguid. The last antecedent before “using a random or sequ…

• #11

  gues, are “not infexible rules.” Post, at 413. On that point, we agree: Linguistic canons are tools of statutory interpretation whose usefulness depends on the particular statutory text and context at issue. That may be all Justice Alito seeks to prove with his discussion and list of “sen- tences that clearly go a…

• #12

  storing them. Perhaps Duguid's interpretive approach would have some appeal if applying the traditional tools of interpretation led to a “linguistically impossible” or contextually implausible 6 Duguid contends that ordinary cell phones are not autodialers under his interpretation because they cannot dial phone n…

• #13

  is superfuous. “It is no superfuity,” however, for Congress to include both functions in the autodialer defnition so as to clarify the domain of prohibited devices. BFP v. Resolution Trust Corporation, 511 U. S. 531, 544, n. 7 (1994). For instance, an autodialer might use a random number generator to determine the…

• #14

  thrust of congressional action since the TCPA's enactment has been to restrict nuisance calls. Because technology “adapt[s] to change,” Duguid argues, the TCPA must be 8 By contrast, Congress did impose broader prohibitions elsewhere in the TCPA. See, e. g., 47 U. S. C. §§ 227(b)(1)(A) and (B) (prohibiting “arti- …

• #15

  Court of Appeals decisions on this question. See Gadelhak v. AT&T Servs., Inc., 950 F. 3d 458, 463–468 (CA7 2020); Glasser v. Hilton Grand Vacations Co., 948 F. 3d 1301, 1306– 1312 (CA11 2020). I write separately to address the Court's heavy reliance on one of the canons of interpretation that have come to play …

• #16

  tence in the New Testament, Matthew 26:75—is not only grammatical; it is perfectly clear. No one familiar with the English language would fail to understand it—even though its meaning is contrary to the one suggested by the series- qualifer canon. The Court writes that the series-qualifer canon “generally refect…

• #17

  to evaluate these canons by conducting what is called a cor- pus linguistics analysis, that is, an analysis of how particular combinations of words are used in a vast database of English prose. See generally Lee & Mouritsen, Judging Ordinary Meaning, 127 Yale L. J. 788 (2018). If the series-qualifer canon were an…