Meta Platforms has gone on trial in federal court in Oakland, California, where a coalition of 29 U.S. states alleges Instagram and Facebook were built in ways that addicted children, harmed their mental health, misled the public about safety and illegally collected young users' data. The states, led by attorneys general from California, Colorado, Kentucky and New Jersey, are pursuing remedies that include ending infinite scroll, removing like counts, tightening age restrictions and deleting algorithms trained on children's data, alongside damages that Meta says could reach $1.4 trillion under the states' methodology, though more recent discussions among the states' lawyers have centered on about $200 billion. Meta denies the claims and says it has strong child-safety measures and insufficient evidence tying platform design to the harms alleged. The roughly seven-week case will include testimony from Mark Zuckerberg and Instagram head Adam Mosseri, follows a 2023 multistate investigation shaped by Frances Haugen's disclosures, and comes after related rulings against Meta in New Mexico and the consolidation of thousands of similar lawsuits before the same judge.