Mark Zuckerberg appeared before a jury today to defend Meta against claims that its social media platforms are dangerously designed to get kids hooked on their sites.

The CEO told the court that Meta has taken action to reduce the prevalence of underage users on Instagram, reported NBC, and has adjusted internal goals to increase a user’s time on the site. Zuckerberg also accused the plaintiff’s attorney, Matthew Bergman of the Social Media Victims Law Center, of mischaracterizing his previous comments. The exchange came after Bergman questioned Zuckerberg about Meta’s age verification policies, Zuckerberg’s personal media coaching, and his compensation as Meta’s chief.

“If you do something that’s not good for people, maybe they’ll spend more time [on Instagram] short term, but if they’re not happy with it, they’re not going to use it over time,” said Zuckerberg. “I’m not trying to maximize the amount of time people spend every month.”

It’s the first time the tech leader testified before a jury about the alleged dangers of social media platforms, and comes after a congressional grilling of Zuckerberg in 2024.

The watershed case in Los Angeles, brought by a 20-year-old user against Meta, TikTok, Snapchat, and YouTube parent company Google, is the first of a consolidated group of lawsuits filed by more than 1,600 plaintiffs alleging the companies knowingly designed dangerous products. TikTok and Snapchat recently settled out of the case being litigated now in L.A,, but several other related lawsuits are moving forward.

The outcome of the trial may influence whether tech giants and their leaders can be held liable for harm to their users’ mental health. Internet companies have mostly been shielded from litigation over their users’ content thanks to a provision in a 92-year-old communications law.

Instagram CEO Adam Mosseri kicked off executive testimonies last week. Mosseri denied claims that social media usage patterns among teens constitute “clinical addiction” — which is a charged topic among mental health professionals and tech leaders. Instead, Mosseri conceded to patterns of “problematic use” among users and denied that Instagram ignored safety concerns in favor of profit. “It’s relative. Yes, for an individual, there’s such a thing as using Instagram more than you feel good about,” he said. “We make less money from teens than any other demographic on the platform.”

Tech watchdogs hope the trial spurs congressional action, including streamlining the controversial Kids Online Safety Act. “What we’re seeing in that courtroom today is exactly what we’ve long known to be true – Mark Zuckerberg built a machine that exploited children for profit, and he knew it,” said Sacha Haworth, executive director of The Tech Oversight Project. “Congress needs to act now to hold Big Tech accountable and stop CEOs like Zuckerberg from exploiting and hurting young people.”

In a public statement released ahead of the trial, company officials argued: “The question for the jury in Los Angeles is whether Instagram was a substantial factor in the plaintiff’s mental health struggles. The evidence will show she faced many significant, difficult challenges well before she ever used social media.”