Period Tracking App Users Win Class Status in Google, Meta Suit

User of the menstrual cycle tracking app Flo largely won class certification in a lawsuit alleging the app surreptitiously shared sensitive health information with Google LLC and Meta Platforms Inc.

Judge James Donato of the US District Court for the Northern District of California on Monday ruled that the users have the same alleged claims and injuries, warranting the certification of a nationwide class and California sub-class of users that will likely number in the millions.

The judge largely rejected arguments by the three defendants, chiding them in the opinion for not providing useful analysis behind their arguments: “The brief filed by defendants was not a triumph of clarity and organization.”

He determined that a number of common factual and legal questions are common across all class members the case, including whether Flo had properly notified users of how their data would be used and how the app used Google and Meta’s software development kits.

The classes would include users who downloaded the app between 2017 and 2019.

Flo’s common privacy disclosures “will permit a jury to conclude in one fell swoop whether a reasonable person would have been on notice of, and so could implicitly consent to” Flo’s data sharing conduct, Donato said. “The relevance of Google and Meta’s privacy disclosures is not obvious in light of plaintiffs’ evidence of secret data sharing, but those disclosures, too, are subject to common proof.”

The ruling comes after Donato last year rejected Google’s motion for summary judgment, finding that only a jury could determine whether the tech giant had violated state and federal privacy laws by obtaining sensitive Flo user data. A jury trial is set for July 14.

The 2021 class action alleged that Flo, which branded itself as the highest rated period tracking app in 2020, commercially exploited the personal data of users, including information about menstruation, ovulation, and pregnancy goals.

It allegedly shared the data with Google and Meta through their SDKs, as well as another ad analytics firm. That now-defunct firm, Flurry LLC, later agreed to pay $3.5 million to settle the claims.

The lawsuit came after Flo settled a similar case with the Federal Trade Commission over its health data sharing practices.

Labaton Keller Sucharow LLP, Spector Roseman & Kodroff PC, Lowey Dannenberg PC were confirmed as class counsel. Gibson Dunn & Crutcher LLP represents Meta. Dechert LLP represents Flo. Willkie Farr & Gallagher LLP represents Google.

The case is Frasco v. Flo Health Inc., N.D. Cal., No. 3:21-cv-00757, 5/19/25.