California plaintiff details social media addiction harms in trial

A 20-year-old woman has taken the stand in Los Angeles County Superior Court to describe what she says was a damaging childhood addiction to social media platforms owned by Meta and Google, in a landmark civil trial that could reshape how tech companies are held accountable for harm to young users. Known in court as Kaley G. M., the plaintiff testified that heavy use of YouTube from age six and Instagram from age nine contributed to long-term mental health issues, including anxiety, depression and body image insecurity, and that she felt compelled to return to her phone even when she understood the toll it took on her wellbeing.

Kaley’s testimony comes amid one of the first bellwether cases drawn from more than 1,600 similar lawsuits consolidated in California, centring on allegations that platforms deliberately engineered addictive features such as infinite scroll, autoplay and constant notifications to keep young users engaged. Snap and TikTok reached settlement agreements with the plaintiffs before the trial began, leaving Meta’s Instagram and Google’s YouTube as the primary defendants.

Represented by attorney Mark Lanier, Kaley recounted for jurors how she struggled to detach from social media even when faced with emotional distress and social pressures. She described a pattern of checking her phone throughout the day, at one point exceeding 16 hours on Instagram, and said that the platforms’ design amplified her need to seek validation through likes, comments and follower counts. Filters that altered appearance, she testified, played a significant role in her negative self-image.

Kaley also spoke about the effects on her personal relationships and daily life, telling the court that her dependency on social feeds strained ties with her family and impaired her schooling and sleep. She told jurors she felt panic when her mother removed her phone and that the constant engagement gave her a “rush” that she found difficult to resist.

The defence has challenged aspects of Kaley’s testimony, with lawyers for both Meta and Google arguing that other factors in her life, including family dynamics and pre-existing challenges, played an important role in her mental health. During cross-examination, Meta’s counsel highlighted inconsistencies in her past statements and noted that she had never received a clinical diagnosis of social media addiction from a health professional, an argument aimed at tempering claims about causation.

A former therapist for Kaley also took the stand earlier in the proceedings, testifying that the connection between her social media use and her sense of self was “closely related” and that experiences online could affect her mood and behaviour. That testimony underscored arguments from the plaintiffs that digital platforms could have profound psychological effects on young people’s development when algorithmic cues and reward systems are involved.

The trial has already seen high-profile testimony from figures within the tech companies. Meta Chief Executive Mark Zuckerberg appeared before the jury to refute claims that Instagram was designed to be addictive to children and to defend the company’s emphasis on user safety, privacy and engagement driven by community building rather than exploitation. Instagram head Adam Mosseri has also testified, distinguishing “clinical addiction” from problematic use and acknowledging trade-offs between safety measures and user experience.

As jurors continue to hear evidence, observers note that the case raises broader questions about the responsibilities of social media companies toward their youngest users and whether product design choices can be construed as contributing to public health harms. Legal experts say that a verdict in favour of the plaintiff that withstands appeal could open the door to significant financial damages and regulatory scrutiny, potentially prompting changes in how platforms cater to minors.