Facebook, Inc. v. Duguid, 592 U.S. 395 (2021), was a United States Supreme Court case related to the definition and function of auto dialers under the Telephone Consumer Protection Act of 1991 (TCPA) to send unsolicited text messages.

of Political Consultants, Inc.,[2] one of the direct challenges to the 2015 amendment that sought to invalidate the autodialer statute of the TCPA, began working its way to the Supreme Court.

Due to the latter complaint, the federal government injected itself into the case to seek its dismissal in favor of Facebook as to protect the constitutionality of the TCPA.

Though Facebook reasserted its stance that their notification system was not an ATDS, the Ninth Circuit had precedence from Marks v. Crunch San Diego, LLC[5] that an ATDS was not limited to devices that dialed numbers sequentially or randomly, but also include those that could dial stored numbers, and that it categorically fit a device that sends "automated, unsolicited, and unwanted" messages to consumers.

[7] In this, the Ninth Circuit determined that the 2015 amendment did add content-based exemptions for free speech and thus was unconstitutional, but was also severable from the rest of the TCPA, leaving in place the autodialer statute.

[9] The Court issued its unanimous decision on April 1, 2021, reversing the Ninth Circuit's latest ruling and remanding the case for further review.

"[11] The Supreme Court's ruling was seen to be favorable to the telemarketing industry, since the decision narrowed the definition of an automatic dialing system of which are regulated under the TCPA.

As few actual automated dialers in use at the time of the decision incorporate the random or sequential number generator, telemarketers would be able to use other automatic dialing systems that do not meet this definition to engage in their business, according to the National Consumer Law Center.