Meta, TikTok and YouTube are heading to a closely watched trial in Los Angeles this week over accusations that their platforms are intentionally designed to addict children and negatively impact young users’ mental health.
Jury selection is set to begin in Los Angeles County Superior Court, marking the first time these companies will present their defence before a jury in this type of case. The trial is expected to run for several weeks and could shape how thousands of similar lawsuits are handled in the future. Snapchat’s parent company, Snap Inc., which was also named in the case, reached a settlement last week for an undisclosed amount.
Central to the lawsuit is a 19-year-old plaintiff identified as KGM, whose case has been chosen as a bellwether, or test case. She alleges that early exposure to social media led to addiction and worsened depression and suicidal thoughts, claiming that companies deliberately built features meant to maximise engagement among young users for profit.
Legal experts say a ruling in favour of the plaintiffs could weaken the protections social media companies typically rely on, including free speech defences and liability shields for user-generated content.
Senior executives, including Meta chief Mark Zuckerberg, are expected to testify. Observers have compared the case to historic lawsuits against tobacco companies that resulted in major industry reforms and large financial settlements.
The tech firms deny the accusations, pointing to safety tools and protections they say have been introduced over the years. Meta and Google have said they strongly disagree with the claims, arguing that youth mental health challenges are complex and cannot be attributed to social media alone. TikTok has not yet commented publicly.
The trial is among a growing number of legal actions across the United States seeking to hold social media companies accountable for alleged harm to children and teenagers.

