Zuckerberg testifies in Los Angeles trial over Instagram harms to children

Mark Zuckerberg took the witness stand in a packed Los Angeles courtroom, defending Meta’s design choices as plaintiffs pressed a dramatic allegation: Instagram and other platforms were engineered to hook children and teens and contributed to long-term mental-health harms.

The testimony came on Feb. 18 in a bellwether civil trial drawn from a consolidated bundle of more than 1,600 lawsuits and set amid a broader wave of thousands of related actions nationwide. The lead plaintiff, identified in court as Kaley G.M., now 20 and from Chico, Calif., sat in the front row as lawyers sought to show that features such as auto-scrolling and internal targets for engagement encouraged compulsive use that produced anxiety, depression and body-image problems.

Zuckerberg repeatedly framed the company’s work as aimed at delivering value to users. “We’re building this thing to be a good thing that has value in people’s lives,” he told jurors. “I want people to have a good experience with it.” He acknowledged that time spent on apps can reflect product improvement. “If you make your product better, then people will use it more,” he said, adding that “looking at the time people spend on our apps is often the best proxy. That’s different from giving our team the goal of trying to increase time.”

Plaintiffs’ attorneys sought to tie those metrics to internal documents and executive statements. They used a 2022 self-review by Adam Mosseri, Instagram’s head, which plaintiffs cited as stating a goal to “ensure the app remains culturally relevant as measured by session time and sharing, particularly with teens.” Mosseri, who testified earlier in the trial, disputed that Instagram should be called an addiction while acknowledging “problematic use.” He also testified about tradeoffs in product decisions, saying “there’s always a tradeoff between ‘safety and speech,’” and that “users don’t like it when they remove options from Instagram.”

The case zeros in on whether product choices were a substantial factor in the plaintiff’s mental-health struggles. Meta representatives pushed back. A company spokesperson said, “We strongly disagree with these allegations and are confident the evidence will show our longstanding commitment to supporting young people,” and noted Meta has made “meaningful changes,” including accounts designed for teenage users. Meta spokeswoman Stephanie Otway told the court that the central question for the jury is “whether Instagram was a substantial factor in the plaintiff’s mental health struggles” and emphasized that the plaintiff “faced many significant, difficult challenges well before she ever used social media.”

Disputes about the plaintiff’s timeline surfaced in court and reporting: plaintiff lawyers said she became “hooked” on social media as young as six, while the plaintiff has said she began using Instagram at nine. Those conflicting accounts underline the factual debates jurors must resolve about exposure, duration and causation.

The trial played out under intense public scrutiny at the Spring Street courthouse before Judge Carolyn Kuhl, with spectators and media filling benches and lines stretching outside. Security details escorted Zuckerberg as he arrived, including federal officers, reflecting the case’s profile and the legal and reputational stakes for Meta. TikTok and Snapchat reached confidential settlements with the plaintiff before the trial; Google and YouTube remain named defendants.

As the trial proceeds, jurors will weigh internal documents, executive testimony and expert evidence to decide whether platform design choices were a substantial causal factor in the harms alleged by the plaintiff. The outcome could reverberate through the hundreds of consolidated suits and shape broader debates over platform accountability, regulation and youth safety online.