Meta (META) will face off against attorneys general from several states in an Oakland, Calif., courtroom Tuesday as part of a major lawsuit alleging that the company violated child safety and consumer protection laws and harmed children’s mental health.

The trial, which begins on Tuesday and is being held in front of District Judge Yvonne Gonzalez Rogers in US District Court for the Northern District of California, is part of a lawsuit filed by 29 states in 2023 and will serve as a kind of bellwether for future proceedings.

California, Colorado, Kentucky, and New Jersey are taking part in the trial, which is expected to include testimony from Meta CEO Mark Zuckerberg and Instagram CEO Adam Mosseri.

In the suit, the plaintiffs claim that Meta “developed and refined a set of psychologically manipulative platform features designed to maximize young users’ time spent on its social media platforms,” including infinite scroll, autoplay, likes, and more.

The states also allege that Meta knew that its apps harmed users, including through increased instances of anxiety, depression, and suicide, but misled them by claiming its products are safe.

The plaintiffs also claim that Meta has violated the Children’s Online Privacy Protection Act (COPPA) by knowingly allowing children under 13 on its platform and collecting their user data without parental consent.

Meta has denied the allegations. The company also opposes the potential damages it faces in the case, which it says could be as high as $1.4 trillion. Meta’s market capitalization is roughly $1.5 trillion.

“The State AGs may call this a landmark case, but their limited claims are unsubstantiated, and their financial demands are vastly disproportionate,” a Meta spokesperson said in a statement.

“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. Rather than sticking to the facts or the law, the states have instead decided to chase an outlandish payout. We stand by our record of creating strong protections for teens, and look forward to making our case in court.”

The case is one of thousands that Meta and social media companies are facing in the US over alleged harms to users.

Earlier this month, a New Mexico District Court ordered Meta to pay $567 million to address teen mental health in the state. The company also must pay $375 million in civil penalties to the state.