Meta Platforms is facing a landmark federal court trial over allegations that Facebook and Instagram were deliberately designed to keep children and teenagers hooked, in what could become one of the biggest legal tests yet for social media companies.

The seven-week trial began on Wednesday in Oakland, California, with Colorado, Kentucky, California and New Jersey leading allegations that Meta designed its platforms to be addictive and misled consumers about their safety.

The case also involves claims from 29 states that Meta illegally collected and used children’s data in violation of federal law.

The trial comes amid growing scrutiny worldwide over the impact of social media on young users. Jury selection began on Wednesday, with opening statements expected on 18 August. Meta founder and CEO Mark Zuckerberg and Instagram head Adam Mosseri are expected to testify.

The potential financial consequences are enormous. Meta has estimated that the states could seek as much as $1.4 trillion in damages, close to the company’s current market value of about $1.5 trillion. The attorneys general have not publicly disclosed how much they intend to seek.

The states are also asking the court to order sweeping changes to Meta’s platforms, including age restrictions, the removal of infinite scrolling and stricter controls on how children’s data is used.

Growing pressure on Meta

The lawsuit, filed in 2023, followed a multistate investigation into the effects of Facebook and Instagram on children and teenagers. The investigation gained momentum after former Meta employee Frances Haugen told a US Senate committee in 2021 that the company knew its products could harm young users and had information that could help make them safer.

Meta has strongly rejected the allegations, saying it has spent years working with parents, experts and law enforcement to improve protections for young people.

The company has also argued that it could not have misled consumers by describing its platforms as addictive because “social media addiction” is not recognised as a psychiatric condition.

Public concern over the issue remains high. A Reuters/Ipsos poll published last week found that 85% of Americans believe social media can be addictive for children, while 61% said social media companies need stronger oversight.

The latest case follows a series of legal setbacks for Meta.

Two cases that have already reached juries resulted in verdicts against the company. Last week, a New Mexico judge ordered Meta to pay $567 million and make changes to its platforms after finding the company responsible for contributing to a children’s mental health crisis in the state.

Meta also settled a lawsuit brought by a Kentucky school district for $9 million earlier this year.

States seek nationwide changes

Beyond financial penalties, the states are seeking broad changes to how Meta operates its platforms.

They want the company to introduce age restrictions, remove algorithms and artificial intelligence models created using children’s data, and eliminate features such as infinite scrolling and notifications.

They are also asking the court to require Meta to change its recommendation systems so they prioritise users’ wellbeing over engagement, as well as introduce strict time limits for young users.

Legal experts say the outcome could have major implications for Meta and the wider social media industry.

“Big damage awards and judicial dictates about features both potentially pose existential threats to social media defendants,” said Eric Goldman, a professor and co-director of the High Tech Law Institute at Santa Clara University School of Law.

The case is also unusual because US District Judge Yvonne Gonzalez Rogers has appointed an advisory jury to answer specific questions during the trial. Such juries are rarely used and their findings will help guide Rogers, although she will ultimately be free to disregard the jury’s conclusions.

Rogers is expected to issue her decision after the trial concludes in October.

The lawsuit is part of a much broader legal battle. More than 3,000 cases brought by school districts, individuals and others against Meta, Snap, Alphabet’s YouTube and TikTok owner ByteDance have been consolidated in federal court before Rogers. Another group of more than 3,300 cases is pending in a Los Angeles state court.

With billions of dollars at stake and demands for nationwide changes to social media platforms, the Oakland trial could set an important precedent for how technology companies are held accountable for the effects of their products on children.