Social media giants face landmark trial over alleged mental health harms to youth

Opening statements began on 5 February, 2026, in Los Angeles Superior Court, in a landmark trial where two of the world’s largest tech companies, Meta and YouTube, are accused of designing platforms that deliberately foster social media addiction among children and teenagers.

The case centres on 20-year-old Kaley G.M. (referred to as K.G.M.), who alleges that her early and prolonged exposure to Instagram and YouTube caused or worsened depression, anxiety, body dysmorphia and suicidal thoughts.

Kaley’s attorney, Mark Lanier, argued that Meta and YouTube deliberately engineered “addiction machines” that manipulated children’s neurobiology, likening the platforms’ features to slot machines. “The swipe, for a child, like Kaley, is the handle of a slot machine,” Lanier said. “But every time she swipes, it’s not for money, but for mental stimulation.”

Lanier emphasised that the companies targeted young users intentionally, motivated by profit. He presented internal documents suggesting Meta aimed to “bring them in as tweens” to secure long-term engagement and ad revenue. YouTube, he alleged, served as a “digital babysitter” designed to hold children’s attention for extended periods.

He further showed an email from Meta CEO Mark Zuckerberg calling for a 12% increase in time spent on platforms to meet company targets.

Both Meta and YouTube deny the allegations.

Defendants argue other factors to blame

Meta’s lawyer, Paul Schmidt, countered that Kaley’s mental health issues stemmed primarily from her upbringing and family environment. He cited medical records showing Kaley had been in therapy from the age of three due to domestic challenges, including verbal and physical abuse.

“Instagram wasn’t a substantial factor in her mental distress,” Schmidt said, adding that social media may have provided a constructive outlet during Kaley’s turbulent childhood.

Schmidt also pointed to Kaley’s own testimony in which she described Instagram as a “creative outlet” and expressed a desire to work in social media.

A YouTube spokesperson said, “The allegations are simply not true. Providing young people with a safer, healthier experience has always been core to our work.” YouTube’s legal team is expected to deliver their full statement later this week.

A bellwether case with national implications

This trial is the first of several bellwether trials scheduled this year involving over 1,500 plaintiffs. It is seen as a test case for determining legal strategies and potential damages in broader litigation over social media harm to youth.

According to Clay Calvert, a technology policy expert at the American Enterprise Institute, the case could “set the tone” for how juries respond to arguments that tech companies are responsible for youth mental health harms caused by design features rather than user-posted content.

Judge Carolyn B. Kuhl instructed jurors not to hold the companies liable for content posted by third parties. Instead, the case hinges on whether the design of features such as endless scroll, autoplay, like buttons, and beauty filters caused psychological harm.

Meta and YouTube have long relied on Section 230 of the Communications Decency Act, which shields platforms from liability for user-generated content. However, the current case challenges this defence by arguing the harm lies in the platform design itself.

Global scrutiny and parallel lawsuits

The case is unfolding amid growing global scrutiny of social media’s impact on youth.

In the United States, over 40 state attorneys general have filed suits against Meta over its alleged role in the youth mental health crisis. A federal bellwether trial involving school districts is expected in June.

Other countries are also taking action. France has passed a law barring children under 15 from social media.

In Australia, companies have disabled 4.7 million underage accounts following a ban on users under 16.

The UK government is also reviewing laws to limit teenage use of social media.

In Singapore, the government is tightening the "gateway" to digital content. By March 31, 2026, a new Code of Practice will require designated app stores to implement age assurance—using methods like AI facial estimation or official IDs—to block users under 18 from downloading inappropriate apps.

While Singapore is studying the effectiveness of Australia’s under-16 ban, it has signaled plans to extend these strict verification requirements directly to social media platforms, moving beyond existing safety settings to mandate technical proof of age.

TikTok and Snapchat were previously named in Kaley’s case but reached confidential settlements before trial. Both remain defendants in other ongoing cases.

The road ahead

Testimony over the next six to eight weeks will include statements from major executives, including Zuckerberg, Instagram chief Adam Mosseri, and YouTube CEO Neal Mohan.

Jurors will also hear from experts, Kaley’s family members, and former Meta employees turned whistleblowers.

Lanier compared the social media industry’s current legal reckoning to the tobacco industry’s landmark 1998 settlement, which imposed sweeping advertising and disclosure reforms.

Safety advocates hope the trial will spur regulatory changes and accountability.

Sacha Haworth, executive director of the Tech Oversight Project, called the case “a crucial moment” to hold tech firms responsible for what she called “deliberately harmful products.”

The trial continues this week, with Kaley and her mother expected to testify in the coming days.