CALIFORNIA (TNND) — A California courtroom became the focal point this week in a high-stakes legal battle over teen mental health as a multistate lawsuit against Meta Platforms entered its second week of trial. The states involved accuse the social media giant of deliberately engineering its platforms—including Instagram and Facebook—to hook young users, while misleading families and regulators about the dangers those products pose to adolescent development. The trial is being closely watched not only for the evidence presented but for what it could mean for the future of tech regulation in the United States. Twenty-nine states and the District of Columbia have joined the broader litigation, but only four states are participating in this initial trial. The remaining states are expected to face Meta in subsequent trials. At the heart of the case is a simple but sweeping accusation: Meta exploited the vulnerabilities of children’s developing brains to maximize engagement, time on site, and advertising revenue, all while publicly downplaying the platforms’ risks.
The states’ legal claims rest on multiple pillars. First, they argue Meta knowingly designed features that encourage compulsive use, such as infinite scrolling, notification alerts, and algorithmically curated content tailored to keep users engaged. Second, they allege the company made false or misleading statements about the safety of its platforms, particularly regarding the potential for harm to young people. Third, the states accuse Meta of improperly collecting personal data from children under the age of 13, which would violate federal child privacy protections under the Children’s Online Privacy Protection Act. The trial will require the states to prove not just that these harms exist, but that Meta’s leadership understood the risks and continued to make decisions that prioritized growth over user well-being. Legal observers say this distinction—between an unfortunate outcome and a knowing, preventable harm—is likely to be the central battle in the courtroom. The evidence so far has reportedly included internal company documents, emails, and testimony intended to demonstrate a pattern of knowledge and concealment, though Meta’s lawyers have pushed back, arguing that social media effects are complex and that the company has invested significantly in safety tools and parental controls.
This week, the trial’s focus is expected to sharpen on the science of adolescent brain development and the specific ways that social media can influence it. Testimony from a psychology professor at San Diego State University began in the first week and is expected to continue, offering expert insight into how social media can alter attention, emotional regulation, and reward processing in young brains. The professor’s work, which has been cited in public debates about the youth mental health crisis, is meant to support the states’ theory that Meta’s products are not merely distracting but psychologically impactful, especially during the critical developmental years before adulthood. Experts anticipate more testimony about both the general neuroscience of social media and Meta’s internal understanding of that research. The states will likely attempt to connect the dots between what Meta knew from its own studies and user research—reports that often showed increased anxiety, depression, and body image issues among teenage users—and the design decisions that amplified those outcomes. In doing so, they hope to establish a direct line between corporate choices and measurable harm, a necessary step in securing a court ruling or settlement that could force major changes to how platforms operate.
Mary Graw Leary, a law professor at The Catholic University of America’s Columbus School of Law, said the central issue for the states is their claim that Meta exploited children’s underdeveloped brains to increase engagement and keep them on its platforms, regardless of the harm it was causing. In an interview, Graw noted that the second week of trial should bring more proof about what Meta knew internally and more evidence about the actual effects of its platforms on children. “I think we’re going to expect a lot more proof about, internally, what Meta knew and a lot more proof about the effect that it has on children,” Graw said. She explained that legal claims built on intentional harm require a showing of knowledge and motive, not merely a correlation between use and poor mental health outcomes. The states’ task, she said, is to convince the judge or jury that Meta’s design choices were made with a clear-eyed understanding of the risks—and that the company proceeded anyway. The testimony from developmental psychologists and neuroscientists will be critical in establishing that Meta had reason to know how its products would affect young users, and the internal corporate communications could reveal whether those concerns were ever raised, dismissed, or overridden for business reasons.
The structure of the trial itself reflects the enormous scale of the litigation. Because so many states have joined the case, the court has split the proceedings into phases. The current trial involves four states, whose arguments and evidence will help shape the legal framework for later proceedings. The remaining 25 states will have their day in court at a later date, potentially benefiting from precedents established in this first trial. Meta, for its part, has consistently denied the core allegations, arguing that its platforms offer positive connection and community, and that the relationship between social media use and mental health is not as straightforward as plaintiffs claim. The company has also noted that it has introduced numerous safety features over the years, including parental supervision tools, age-verification measures, and content restrictions for minors. But the states are likely to argue that those measures came too late and were inadequate to undo the harm already done. One of the most anticipated moments of the trial will be testimony from Meta CEO Mark Zuckerberg, who is expected to take the stand at some point, though the exact timing remains unclear. His appearance could be a dramatic centerpiece, given his role as the public face of the company and his past testimony before Congress, where he faced pointed questions from lawmakers about child safety and online harm.
As the trial enters its next phase, the implications reach far beyond the four states at the table. A verdict against Meta could lead to court-ordered changes to platform design, new limits on data collection from minors, and increased transparency requirements for algorithms that serve content to young people. It could also strengthen the hand of the other 25 states in their upcoming cases, and potentially inspire further legislation at both the state and federal levels. For families, the trial represents a moment of reckoning over the role of social media in the daily lives of children and teenagers. The outcome may not resolve the broader societal debate about screen time, but it could set a powerful legal precedent that companies have a duty to protect young users from foreseeable harm. With expert testimony still to come, internal documents to be examined, and a tech mogul expected in the witness chair, the trial is far from over. The courtroom in California has become the stage for one of the most consequential legal challenges to the modern attention economy, and the world is watching to see whether the law will hold social media platforms accountable for what their own research has long suggested: that their products were built to keep kids scrolling—no matter the cost.