Meta is facing one of the most consequential legal battles in the U.S. social media industry as a federal trial begins in California over allegations that Facebook and Instagram were designed in ways that harmed children and encouraged prolonged, addictive use.

The case, being heard in Oakland, brings together a coalition of 29 states and territories and could have consequences far beyond Meta. Attorneys general are seeking financial penalties and changes to how social media platforms are designed, marketed and operated for younger users.

At the center of the Meta child safety trial are allegations that the company knowingly developed features that encouraged children and teenagers to remain on its platforms for extended periods. State officials also accuse Meta of misleading the public about the safety of its services and improperly collecting information from children under 13.

Meta has denied wrongdoing and argues that it has spent years developing tools and policies intended to improve safety for young users. The company is expected to challenge the states’ interpretation of its internal research and product decisions during the proceedings.

The legal stakes are unusually high.

Meta has said the states could seek penalties reaching approximately $1.4 trillion if they prevail, a figure that would represent an extraordinary financial consequence for the company. The amount is based on the states’ potential penalty calculations rather than an award already imposed by the court.

The trial also comes after several significant developments in other cases involving Meta.

In March, a New Mexico jury found Meta liable in a case alleging that its platforms endangered children and ordered the company to pay $375 million. A later court ruling added another $567 million in penalties and imposed additional child-safety measures, bringing the total liability in that New Mexico matter to $942 million. Meta has indicated that it plans to appeal.

Those rulings have strengthened calls for tougher regulation of social media companies.

New Mexico officials are now pushing for additional legislation focused on online child safety, including measures that could extend beyond conventional social media platforms to artificial intelligence systems and chatbots.

The California federal case has a different legal structure, but its potential impact could be just as significant.

U.S. District Judge Yvonne Gonzalez Rogers will oversee the proceedings. An advisory jury has been selected to provide guidance, although its decision will not be legally binding. The judge will ultimately determine the outcome.

That unusual arrangement could make the proceedings particularly important for the technology industry.

The states are seeking more than financial penalties. Their demands could include restrictions on certain product features, stronger age protections, changes involving algorithms and limits on how platforms use data associated with children.

The broader regulatory debate is already expanding.

Lawmakers and state officials across the country are examining age verification, parental controls, children’s privacy, notification systems, recommendation algorithms and the design of features that encourage continuous engagement.

The Meta child safety trial could provide a legal framework for some of those debates if the court ultimately determines that certain product-design decisions violated consumer-protection or federal privacy laws.

The case also arrives as Meta faces a much larger wave of litigation.

Thousands of claims have been filed by families, school districts and other plaintiffs alleging that social media platforms contributed to youth mental-health problems or were intentionally designed to encourage addictive behavior. Meta and other technology companies have generally denied the allegations.

A landmark Los Angeles case earlier this year found Instagram and YouTube liable in a lawsuit alleging that the platforms were designed to addict young users. That verdict has added to pressure on technology companies and could influence future litigation.

For Meta, the federal case represents more than another courtroom dispute.

A significant loss could lead to substantial financial exposure, regulatory changes and additional lawsuits. A victory could strengthen the company’s position against similar claims and make it more difficult for state officials to impose sweeping changes through litigation.

For parents and technology users, the proceedings are part of a larger question about who should be responsible when digital products are designed to maximize engagement among young users.

As the Meta child safety trial moves forward, the outcome could help define the boundaries between product design, consumer protection, children’s privacy and corporate responsibility.

The decision may ultimately affect not only Meta but the wider social media industry, which is already facing growing demands for stronger protections for children online.

Source: Associated Press, Reuters, California Department of Justice, U.S. District Court for the Northern District of California, and related U.S. state litigation records.