Landmark Los Angeles trial opens over alleged social media addiction in children

Jurors in downtown Los Angeles heard opening arguments in a bellwether trial that accuses Meta and YouTube of designing features intended to addict children and harm their mental health. The case, filed on behalf of a plaintiff identified as K.G.M. and described in filings as a 20-year-old California woman, opened at the Spring Street Courthouse with a flurry of internal documents and dramatic courtroom imagery.

Mark Lanier, the plaintiffs’ lead attorney, framed the dispute in blunt terms and used a simple prop to sharpen his point. Pulling three wooden children’s blocks from his bag, he stacked them as he outlined his central thesis. “This case is as easy as ABC,” he told the jury, explaining that the letters stood for “Addicting, brains, children.” Lanier portrayed Instagram and YouTube as engineered to capture and sustain youthful attention, saying the companies “engineered addiction in children's brains,” and arguing they “didn’t just build apps, they built traps.” He added, “They didn’t want users, they wanted addicts.”

The complaint presented to jurors alleges that the companies borrowed techniques from gambling and tobacco industries, arguing that the platforms were “Borrowing heavily from the behavioral and neurobiological techniques used by slot machines and exploited by the cigarette industry,” and that defendants “deliberately embedded in their products an array of design features aimed at maximizing youth engagement to drive advertising revenue.” Plaintiffs introduced a slew of internal emails, documents and in-house studies during opening statements to support claims that the companies knew their designs targeted young brains.

Meta’s defense pushed back on both the characterization and the causal link. Paul Schmidt, the lawyer who delivered Meta’s opening, told jurors the trial’s central legal question is narrower: “The core question in the case is whether the platforms were a substantial factor in KGM’s mental health struggles.” Schmidt emphasized elements of the plaintiff’s health record, noting a history of emotional abuse, body image issues and bullying, and he highlighted disagreement among researchers over whether heavy social media use should be described as addiction.

The Los Angeles case is the first in a series of high-profile trials this year that seek to hold major social media companies responsible for harms to youth. TikTok and Snap were originally named as defendants in the litigation but settled for undisclosed sums before this trial began. Courtroom strategists on both sides signaled that causation and the meaning of “addiction” will be the central battlegrounds, with expert testimony likely to be pivotal.

The trial is expected to run six to eight weeks and could feature testimony from current and former executives; court filings and pretrial filings indicate that senior figures, including Meta’s CEO, are expected to testify at some point in the proceedings. A separate case against Meta opened in New Mexico the same day, underscoring the national scope of litigation threading through state and federal courts.

Legal scholars and public-health advocates have compared the litigation’s claims to previous campaigns against tobacco and gambling, arguing that whatever the outcome, the trial could set important precedents about product design, corporate responsibility and the regulation of platforms that reach children. For now, jurors will spend weeks weighing dueling narratives backed by reams of internal material, scientific testimony and sharply contrasting views about how social media shapes young lives.