A coalition of States suing Meta Platforms over claims Facebook and Instagram were designed in ways that harmed young users’ mental health will begin making its case on Tuesday in California at a federal court in a trial that could reshape some of the most popular apps on the planet.

Attorneys for Colorado, California, New Jersey and Kentucky, who are leading a bipartisan group of 29 states, will give their opening statements before an eight-person jury in Oakland that is serving expressly in an advisory capacity for U.S. District Judge Yvonne Gonzalez Rogers, who will ultimately decide the case.

The trial will test the four States’ allegations that Meta designed Facebook and Instagram to be addictive to children and teens and misled consumers about the safety of the platforms for young users. It will also address the claims of all 29 States accusing Meta of improperly collecting and using children’s personal data while they used the firm’s platforms in violation of federal law.

Attorneys for Meta are expected to tell the jury that the company has made a huge effort to keep kids safe online. The company has argued that it has not made misleading statements about safety and the States have failed to present any evidence of actual harm to their residents.

Meta founder and CEO Mark Zuckerberg is expected to testify during the multi-week trial, as is Instagram head Adam Mosseri.

Biggest test yet

In terms of potential damages and implications for Meta, experts have said the trial is the biggest test yet of youth social media litigation and comes amid a broader reckoning across the globe over social media’s effects on young users. Meta has said the penalties could be as high as $1.4 trillion, near the company’s market cap of $1.5 trillion.

Published - August 18, 2026 10:14 pm IST