Mark Zuckerberg testified Wednesday in a Los Angeles courtroom in an unprecedented social media trial questioning whether Meta’s Instagram deliberately addicts and harms children. The Meta CEO said the company moved away from using time-spent metrics to measure platform success, but internal documents the plaintiff’s attorney presented appeared to contradict his earlier congressional testimony that employees had not been given explicit goals to boost engagement.
The case is one of three bellwether trials selected to shape how thousands of similar lawsuits against social media companies proceed. Bereaved parents sat in the courtroom audience as the plaintiff’s attorney challenged Zuckerberg on the company’s age verification policies and cosmetic beauty filters.
Mark Zuckerberg testified Wednesday in Los Angeles that Meta consciously moved away from using time-spent metrics to measure Instagram’s success, but internal documents presented by the plaintiff’s attorney appeared to contradict his prior congressional testimony that employees were never given explicit goals to boost engagement time.
During questioning by plaintiff’s attorney Mark Lanier, Zuckerberg said he still agrees with a previous statement that the existing body of scientific work has not proved that social media causes mental health harms. When Lanier asked whether people tend to use something more if it is addictive, Zuckerberg replied, “I don’t think that applies here.”
The trial centers on a now 20-year-old woman identified by initials KGM, who claims her early use of Instagram addicted her to the technology and exacerbated depression and suicidal thoughts. Meta Platforms and Google’s YouTube remain as defendants; TikTok and Snap have settled.
Internal Documents Challenge Congressional Testimony
Lanier presented internal documents that appeared to contradict Zuckerberg’s testimony. Zuckerberg acknowledged the company previously had goals associated with time spent on the platform, but said he and Meta made a conscious decision to shift away from those metrics. He said he believes that “if something is valuable, people will use it more because it’s useful to them.”
The distinction matters because optimization for user time-spent creates the conditions for addictive engagement, a central claim in the case. Zuckerberg’s assertion that the company prioritizes utility over engagement duration forms the backbone of Meta’s defense.
Courtroom Scrutiny: Media Coaching and Platform Safety
Lanier also questioned Zuckerberg extensively about internal feedback he received on his public presentation. The attorney presented an internal document about feedback on Zuckerberg’s tone of voice on social media, instructing him to come off as “authentic, direct, human, insightful and real” and to avoid appearing to “try hard,” or be “fake, robotic, corporate or cheesy.”
Zuckerberg pushed back against suggestions he had been coached on how to respond to questions, saying those offering the advice were “just giving feedback.” He noted that regarding his media appearances and public speaking, “I think I’m actually well known to be sort of bad at this.”
On age verification, Lanier spent considerable time pressing Zuckerberg on Meta’s policies. After a lengthy back-and-forth, Zuckerberg reiterated that the company’s policy restricts users under age 13 and that Meta works to detect users who have falsified their ages.
The attorney also grilled Zuckerberg about cosmetic beauty filters, mirroring questioning of Instagram head Adam Mosseri the previous week. Zuckerberg said he did not believe there was sufficient evidence pointing to harm the filters could cause and said he maintains a “high bar” for removing tools or features that limit user expression.
Lanier pointed to external experts Meta had consulted to assess the filters and their potential impacts. All 18 experts raised concerns about the filters’ effects, the attorney said.
Meta’s Defense and Advocacy Response
Meta’s attorney Paul Schmidt said in opening statements that the company does not dispute that KGM experienced mental health struggles, but disputes that Instagram played a substantial factor. He pointed to medical records showing a turbulent home life, arguing she turned to Meta’s and YouTube’s platforms as coping mechanisms rather than being driven to them by addictive design.
However, Josh Golin, executive director of the children’s advocacy group Fairplay, characterized the testimony as disingenuous. “All Mark Zuckerberg accomplished with his testimony today was to prove yet again that he cannot be trusted, especially when it comes to kids’ safety,” Golin said. “Under oath, Meta’s CEO testified that his company does not have an objective to increase users’ time spent on Instagram. But we know Zuckerberg and his fellow executives prevented Instagram from getting rid of features like visible like counts and plastic surgery filters — features that are by their very nature addictive.”
The case is one of three bellwether trials selected to shape outcomes in thousands of similar lawsuits against social media companies. Bereaved parents are sitting in the courtroom audience. Meta faces a separate trial in New Mexico that began the previous week.