Mark Zuckerberg Testifies in Landmark Trial Over Social Media Addiction Claims

Mark Zuckerberg appeared in a California court on Wednesday, defending his leadership of Meta Platforms in a closely watched trial examining whether social media platforms are addictive for children.

The case marks Zuckerberg’s first appearance before a jury following years of public scrutiny over Meta’s impact on young users. The company owns Instagram, Facebook and WhatsApp, all central to debates over teen mental health.

The trial, which also names YouTube—owned by Google—as a defendant, is being closely monitored due to its potential implications for thousands of similar lawsuits across the United States.

The Plaintiff’s Case

The lead plaintiff, identified by her initials K.G.M., alleges that she was harmed after using Instagram and YouTube from a young age. Her legal team argues that social media companies knowingly designed platforms to foster addictive use among children despite awareness of potential mental health risks.

During cross-examination, attorney Mark Lanier confronted Zuckerberg with internal emails. In one 2015 message, Zuckerberg outlined a goal to increase “time spent” on Meta platforms by 12% and to reverse a decline in teenage engagement. In earlier correspondence, he had described time spent as “the most concerning” performance metric.

Lanier pointed out that at the time those emails were written, the plaintiff was only nine or 10 years old and already using Instagram.

Zuckerberg acknowledged that increasing time spent had once been a company objective but maintained that this is no longer how Meta operates.

“If something is valuable, people tend to use it more,” he said.

Lanier countered that individuals addicted to something also tend to increase their usage.

“I don’t know what to say to that,” Zuckerberg responded. “I think that may be true, but I don’t know if that applies here.”

Wider Industry Scrutiny

Last week, Adam Mosseri, head of Instagram, also testified, disputing claims of addiction. He argued that even prolonged usage—such as 16 hours in a single day—does not necessarily constitute addiction.

Although Neal Mohan had been expected to testify, he is no longer scheduled to appear, according to reports.

Meanwhile, TikTok and Snapchat, which were also initially named in the lawsuit, reached settlements shortly before trial. The terms were not disclosed.

The case is part of a broader wave of litigation brought by families, school districts, and state prosecutors. In one related matter, 29 state attorneys general are urging a California federal court to order platforms to implement immediate safeguards, including removing accounts belonging to users under 13.

Global Policy Response

Concerns over youth social media use are prompting legislative action globally. Australia implemented a ban on social media accounts for individuals under 16 last year. The United Kingdom, Denmark, France and Spain are considering similar restrictions.

The California trial is expected to last several weeks and may include testimony from former Meta employees who have publicly criticised the company’s internal practices.

With thousands of related lawsuits pending, the outcome could significantly shape the future regulatory landscape for social media companies worldwide.