Meta CEO Mark Zuckerberg is set to testify Wednesday in a landmark California trial examining whether social media platforms are deliberately designed to foster addiction among young users.
The case, focusing on Instagram and other platforms owned by Meta, could set a precedent for thousands of lawsuits filed by American families alleging that tech giants harm children’s mental health.
Zuckerberg, 41, will be the most high-profile witness to address these issues directly before a jury, marking the first time he will speak publicly under oath about the safety and design of his company’s global platforms. His controversial reputation has loomed over the proceedings, with Meta’s lawyers taking special care during jury selection to exclude California residents perceived as overly hostile toward the Facebook founder.
The 12-member jury in Los Angeles will hear testimony through late March to determine whether Meta’s Instagram and Google-owned YouTube bear responsibility for the mental health struggles of Kaley G.M., a 20-year-old California resident who has been an active social media user since childhood. Kaley began using YouTube at age six and Instagram at 11, later adding TikTok and Snapchat.
At issue is whether the platforms were intentionally engineered to encourage compulsive use among young people, contributing to anxiety, depression, eating disorders, and other mental health problems. The trial focuses on app design, algorithms, and personalization features, as U.S. law largely shields platforms from liability for user-generated content.
TikTok and Snapchat, also named in the complaint, reached confidential settlements with the plaintiff prior to trial.
Early Testimonies and Controversy
Instagram chief Adam Mosseri was the first Silicon Valley executive to testify on February 11, framing social media overuse as “problematic use” rather than clinical addiction, echoing Meta’s preferred terminology.
“I’m sure I’ve said I was addicted to a Netflix show when I binged it really late one night, but I don’t think that’s the same thing as clinical addiction,” Mosseri told jurors.
The courtroom has been filled with grieving families, including mothers whose teenage children died by suicide, many of whom camped overnight in the rain to secure seats. The plaintiff’s lawyers called psychiatrist Anna Lembke to testify that social media can act as a “gateway drug,” rewiring young brains toward addictive behaviors.
Internal Meta emails have been scrutinized, including correspondence surrounding Zuckerberg’s 2020 decision to permit cosmetic surgery filters on Instagram. These filters, which allow users to visualize cosmetic procedures, were controversial within the company, with some executives warning they could harm young girls, while others pushed to reinstate them to remain competitive against TikTok.
YouTube CEO Neal Mohan was originally scheduled to testify but the plaintiff’s lawyers announced plans to call another YouTube executive instead.
Broader Legal Implications
The Los Angeles trial runs concurrently with a similar nationwide case in federal court in Oakland, California, which could trigger additional trials in 2026. Meta is also facing legal scrutiny in New Mexico, where prosecutors allege the company prioritizes profits over protecting minors from sexual predators.
This case marks a critical test of whether tech giants can be held accountable for the design of their platforms and the growing mental health crisis among young social media users.
