Zuckerberg was very reserved at first, an AFP journalist in the courtroom reported, but then he began to grow animated, showing signs of annoyance, shaking his head and waving his hands as he turned toward the jury.
The 12 jurors in Los Angeles heard the increasingly testy testimony as plaintiff lawyer Mark Lanier pressed Zuckerberg on age verification and his guiding philosophy for making decisions at the vast social media company he controls.
The trial is set to last until late March, when the jury will decide whether Google-owned YouTube and Meta’s Instagram bear responsibility for the mental health problems suffered by Kaley GM, a 20-year-old California resident who has been a heavy social media user since childhood.
Kaley GM started using YouTube at age 6, Instagram at 9, then TikTok and Snapchat.
Under-13s are not allowed on Instagram, and Lanier pressed Zuckerberg on the fact that Kaylee had easily signed up for the platform despite rules that were buried deep in the user agreement, which he said a child could not be expected to read.
‘Right place now’
Zuckerberg was confronted with an internal document that said Instagram had four million users under 13 in 2015, at the time of the plaintiff’s adoption of the app, and that 30% of all 10- to 12-year-olds in the United States were users.
Zuckerberg said that “we’re in the right place now” when it comes to age verification, and that new tools and methods would be added over time.
Lanier went on to argue that when enforcement of these rules were more lax, young people like Kaley were also subject to Meta’s efforts to increase time spent on its world-dominating apps.
Zuckerberg admitted that “we did used to have goals around time” but that the company’s goal was always to “build useful services that help people connect to the people they care about and learn about the world”.
The trial will determine whether Google and Meta deliberately designed their platforms to encourage compulsive use among young people, damaging their mental health in the process.
The case, with two similar trials scheduled in Los Angeles this summer, aims to establish a standard for resolving thousands of lawsuits that blame social media for fuelling an epidemic of depression, anxiety, eating disorders and suicide among young people.
The proceedings focus solely on app design, algorithms and personalisation features, since US law grants platforms nearly complete immunity from liability over user-generated content.
TikTok and Snapchat, also named in the complaint, reached confidential settlements with the plaintiff before the trial began.
The Los Angeles proceedings are running parallel to a similar nationwide case before a federal judge in Oakland, California, which could result in another trial in 2026.
Meta is also facing trial this month in New Mexico, where prosecutors accuse the company of prioritising profits over protecting minors from sexual predators.
-Agence France-Presse