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A banner with names of young people who advocates say died as a result of social media, outside a U.S. Courthouse in Oakland, Calif., on Aug. 18.Noah Berger/The Associated Press

A landmark social media trial began this week, as Meta Platforms Inc. faces dozens of U.S. states that have accused the company of violating federal law by improperly collecting and using children’s personal data.

Meta could be forced to pay out more than US$1-trillion if found liable. Here’s a breakdown of the trial, and how its results could affect Canadians.

Why is Meta being sued?

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Meta CEO Mark Zuckerberg during a U.S. Senate Judiciary Committee hearing, in Washington, in January, 2024.BRENDAN SMIALOWSKI/AFP/Getty Images

A bipartisan group of 29 U.S. states are suing Meta Platforms, seeking potentially tens of billions or even hundreds of billions of dollars in penalties plus changes to how Meta does business.

The 233-page lawsuit, filed three years ago, alleges Meta falsely represents that its features are safe and not designed to induce compulsive and extended engagement by young users. It cites features and metrics such as likes, face and body image manipulation filters, infinite scroll and autoplay as some of the addictive measures geared toward children.

The lawsuit also claims that Meta “understands the cyclical and harmful nature of its psychologically manipulative features, but persists in subjecting young users to those features, choosing to downplay and deny the harmful aspects of its Platforms instead of correcting those problems.”

Meta chief executive officer Mark Zuckerberg is expected to testify.

Meta denies the accusations. “We’ve built safeguards into our platforms to support parents, and to help teens connect with their friends and explore their interests, in a protected environment,” it said in a statement released earlier this month. “We’ve consulted with parents, policymakers and safety experts throughout this process to ensure their expertise informs the changes we make.”

The trial is being held in federal court in Oakland, Calif., and is expected to last six weeks. It’s one of the biggest cases ever, in terms of both potential payout and the number of parties involved. It is being compared with the lawsuits that led to the Tobacco Master Settlement Agreement in 1998. That resolution was between 46 U.S. states and the four largest U.S. tobacco companies, which agreed to change marketing tactics and pay states for medical expenses directly related to smoking.

The Meta case is being heard in front of an eight-person advisory jury, and U.S. District Judge Yvonne Gonzalez Rogers will determine Meta’s liability. Advisory juries give verdicts on specific issues selected by the judge, but Judge Rogers is free to disregard their findings in her final decision.

If the company is found liable, Judge Rogers could impose civil penalties and order changes to Facebook and Instagram. Meta has said penalties could be as high as US$1.4-trillion, close to the California-based company’s market value. The attorneys-general have not publicly disclosed what amount they are seeking.

Hasn’t Meta been sued for this already?

The lawsuit is one of more than 3,000 lawsuits filed by school districts, individuals and others in federal court against Meta, Snap Inc., YouTube parent Alphabet Inc. and TikTok parent ByteDance Ltd. Some of these have been centralized before Judge Rogers.

A second group of more than 3,300 lawsuits brought largely by individuals against the companies is pending in a Los Angeles state court.

Trials in two cases that have already gone to juries resulted in verdicts against Meta. Earlier in August, a New Mexico judge ordered the company to pay US$567-million and make changes to its platforms after finding the company responsible for fuelling a children’s mental health crisis in the state. The company also settled a lawsuit brought by a Kentucky school district that had been slated for trial in June, with the terms publicly unknown.

But experts have called this trial one of the biggest tests yet of social media litigation because of its size and the potential large monetary consequences for Meta. As well, it is taking place during a broader reckoning across the globe over social media’s effects on young users.

Who has testified so far?

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Former Facebook employee Arturo Béjar speaks during a rally in Washington, in January, 2024.Jose Luis Magana/The Associated Press

Arturo Béjar, the first witness and a former engineering director at Meta Platforms, said Mr. Zuckerberg fostered a culture that treated child safety as secondary to growth and engagement on Facebook and Instagram.

Mr. Béjar also said Meta had technology to flag and require verification from the potentially millions of users suspected to be under 13, but turned a blind eye through a “don’t ask, don’t tell” policy because keeping them was financially profitable over the longer term.

“Where the youngest kids are is where the users are going to be in the future,” he said.

How can this case affect Canadians?

The decision made in California could ultimately affect how social platforms are designed. The 29 states want Meta to implement age restrictions on users, delete all algorithms and AI models made with children’s data, and eliminate features such as infinite scroll and notifications. Such changes would fundamentally affect Facebook’s and Instagram’s business models.

Prior to the trial, Ottawa introduced Bill C-34 – the Safe Social Media Act – which would block users under 16 from having social media accounts. A company could seek an exemption if it “provides adequate safeguards in the regulated social media service,” the bill states. It followed a similar bill introduced in Australia in 2025.

Meta has blocked Canadian news on Facebook and Instagram since 2023, in response to Bill C-18 (the Online News Act). The act requires digital platforms to pay news companies for news stories posted on their platforms. In January, Ottawa was in talks with Meta to reinstate news on the platforms.

With reports from Marie Woolf and Reuters