The woman known as KGM testified Thursday in Los Angeles County Superior Court that she became addicted to YouTube at age six, moved to Instagram at nine, and by ten was depressed and engaging in self-harm. She is now 20 and works as a personal shopper at Walmart. She still uses social media. 'I can't, it's too hard to be without it,' she told the court. Her case is the lead plaintiff action in a consolidated lawsuit against Meta and YouTube, and the first of more than 20 bellwether trials designed to gauge jury reactions and set legal precedent for a pool of more than 1,600 plaintiffs, including more than 350 families and 250 school districts. The legal architecture mirrors the tobacco litigation of the 1990s. KGM's lawyers allege that specific platform features — infinite scroll, video autoplay, like buttons — are deliberately designed to create addictive engagement patterns and exploit teenagers' desire for validation. The claim is not that social media is harmful by accident but that the addiction mechanism is a product design choice. This is the distinction that matters: if the court finds that these features constitute intentional design for addiction, the companies face financial penalties and mandates to change how their platforms function. The structural parallel to tobacco is that the industry knew about harm, designed for engagement anyway, and profited from the dependency. TikTok and Snap were originally defendants in KGM's case but reached settlement agreements just before trial, with terms not publicly disclosed. The pre-trial settlements are significant: two of four defendants chose to pay rather than face a jury verdict on the addiction question. Meta and YouTube deny wrongdoing. YouTube spokesperson José Castañeda called the allegations 'simply not true' and said providing young people with a 'safer, healthier experience has always been core to our work.' Meta filed a brief Wednesday arguing KGM's mental health issues were exacerbated by a difficult home life. 'The evidence will show she faced many significant, difficult challenges well before she ever used social media,' said Meta spokesperson Liza Crenshaw. The defense strategy is causation, not denial of product design. Meta's argument — that KGM had pre-existing vulnerabilities including an occasionally abusive home life — is the same playbook tobacco companies used: the plaintiff was already damaged, our product didn't cause the harm. KGM testified that her mother had occasionally been abusive and hit her, but also that her mother was a loving parent working hard to raise three children, and that she still lives with her. The question the jury must resolve is not whether KGM had other risk factors but whether the platform design was a substantial contributing cause. Her former therapist Victoria Burke, who treated KGM at ages 13 and 14, testified Wednesday that she diagnosed KGM with body dysmorphic disorder and social phobia, and that social media was a 'contributing factor' in her mental health issues. The testimony from platform executives adds structural weight. Mark Zuckerberg, Adam Mosseri (head of Instagram), and Cristos Goodrow (VP of engineering at YouTube) have all testified over the past two weeks. The trial began in late January and is expected to continue for another two to four weeks. Upcoming witnesses include KGM's mother Karen and child and adolescent psychiatrist Kara Bagot. The specificity of the witness list — therapist diagnosis, parental testimony, psychiatric expert, platform executives — follows the tobacco litigation template precisely: establish the harm, establish the product design, establish the company's knowledge. The extraction question is the core of this case. Social media platforms convert user attention into advertising revenue. The allegation is that this conversion is optimized through features specifically designed to create compulsive use patterns, and that the cost of this optimization falls disproportionately on young users whose neurological development makes them more susceptible to addiction mechanisms. If the plaintiffs prevail, the precedent applies not just to these companies but to any attention-economy product that uses similar engagement design patterns. The 250 school districts among the plaintiffs signal that the harm is being measured not just in individual mental health costs but in institutional costs — the burden on educational systems dealing with the downstream effects of platform-designed addiction.
