Meta Platforms, the parent company of Facebook and Instagram, is facing what experts are calling the biggest legal test yet of social media’s effects on young users, as a coalition of 29 US states began presenting its case this week in a California federal court trial that could force sweeping changes to the company’s apps.
The trial got under way on Tuesday in Oakland, California, where lawyers for California, Colorado, Kentucky and New Jersey leading the broader 29-state, bipartisan coalition delivered opening statements before an eight-person jury. The case originated from a unified lawsuit brought by the coalition of state attorneys general in 2023, with California Attorney General Rob Bonta co-leading the effort alongside his counterparts in the other lead states.
The trial is being presided over by Judge Yvonne Gonzalez Rogers and is expected to last approximately six weeks. Jurors are expected to issue an advisory verdict, though the ultimate decision will rest with the presiding judge.
The lead states have accused Meta of designing Facebook and Instagram to hook young users, contributing to harms including anxiety, depression and even suicide, while misleading consumers about the platforms’ safety. Separately, all 29 states have accused Meta of violating federal law by improperly collecting and using children’s personal data. The lawsuit specifically alleges that Meta knew children under the age of 13 were using Instagram and Facebook, a violation of the company’s own stated policies and that it collected personal information about them without parental consent, in breach of the Children’s Online Privacy Protection Act (COPPA).
Prosecutors argue that keeping children on the platforms for longer periods boosted Meta’s advertising revenue, even as it came at the cost of young users’ mental health. The states are seeking financial penalties as well as nationwide changes to the platforms, including age restrictions and limits on features such as infinite scroll.
Meta founder and Chief Executive Officer Mark Zuckerberg and Instagram head Adam Mosseri are expected to testify during the trial, alongside current and former employees and other witnesses, potentially offering insight into how the company assessed platform risks, interpreted internal research and made decisions about engagement-driving features. However, attorneys general said on the trial’s opening day that they had not yet finalised whether Zuckerberg would ultimately be called to the stand.
The case follows a multi-state investigation into the impact of Facebook and Instagram on children and teenagers, which gained significant momentum following disclosures made by former Meta employee and whistleblower Frances Haugen.
A Meta spokesperson pushed back on the allegations in a statement, arguing that the states’ claims are limited and unsubstantiated and that the financial demands being sought are “vastly disproportionate.” The spokesperson added: “The AGs offer no proof anyone in their states was misled, claim benign features like having an additional Instagram account somehow harmed their residents, and attempt to penalize Meta for industry-wide challenges like age verification,” while maintaining that the company stands by its record of building protections for teenagers
The states are seeking as much as $200 billion in damages from Meta over the allegations. Separately, some estimates place Meta’s potential total exposure in the case as high as $1.4 trillion, factoring in the scale of penalties and platform changes being sought. Meta’s shares fell 3.71% to $547.84 during Tuesday’s trading session, though the decline cannot be attributed solely to the trial.
Meta, which said in late July that an average of 3.6 billion people use its platforms daily, is expected to appeal any adverse ruling, potentially all the way to the US Supreme Court.
The Oakland trial is considered a bellwether case, a test case whose outcome could heavily influence a much larger body of litigation. Meta is currently facing federal multidistrict litigation comprising more than 2,407 active cases as of March 2026, filed by individuals, school districts and attorneys general from 42 states. Meta and other major social media and tech companies, including Snap Inc, TikTok parent ByteDance, and YouTube parent Alphabet, are collectively facing thousands of lawsuits from states, municipalities, school districts and individuals over allegations that their products harm young users. Meta has previously said the sheer volume of litigation it faces could seriously affect its business and financial results.
The current trial traces its roots back to October 2023, when dozens of US states first filed coordinated federal and state lawsuits against Meta. At the time, a coalition of 33 states filed a joint federal complaint in California alleging violations of COPPA and various state consumer protection laws, while eight additional states pursued similar claims separately in state courts, and more states joined in the following weeks, eventually growing the coalition to 41 states and the District of Columbia. Colorado Attorney General Phil Weiser, at the time of the original filing, described the situation as a “youth mental health crisis” in the United States, arguing that young people had been “brought down rabbit holes” by the platforms’ design.
With opening statements now concluded and testimony under way, the Oakland trial is expected to run for roughly six weeks, with its outcome likely to shape not only Meta’s own legal and financial exposure, but also the broader wave of litigation facing the social media industry over the mental health effects of its products on children and teenagers.
