US court to decide if Instagram, YouTube are designed to increase social media addiction

The plaintiff at the centre of the case

The main plaintiff is a young woman identified in the court records as KGM. According to filings, she created a YouTube account as an eight-year-old, joined Instagram at nine, TikTok’s predecessor Musical.ly at 10, and Snapchat at 11. She said that years of constant use left her struggling with depression, anxiety, and body image issues.

Since this case pertains to the design of these platforms, the lawyers representing the plaintiffs have been explicit about the scope of their claim. “Borrowing heavily from the behavioral and neurobiological techniques used by slot machines and exploited by the cigarette industry, Defendants deliberately embedded in their products an array of design features aimed at maximizing youth engagement to drive advertising revenue,” the lawsuit says.

Those features include endless feeds that never naturally stop, algorithms that learn user preferences, notifications that pull users in repeatedly, and social metrics such as likes, streaks, and views that reward constant presence. The claim is straightforward: minors were not merely exposed to content, but they were drawn into feedback loops built to hold their attention, and the harm followed from that design choice. That vulnerability, the plaintiffs argue, was central to a business model driven by advertising revenue.

In court filings, the plaintiffs describe the harm as the “foreseeable outcome of how these platforms were built.” The complaint says companies “studied efforts” to keep young users engaged, borrowing techniques “used by slot machines and exploited by the cigarette industry.”

Settlements don’t make those allegations disappear. The companies remain defendants in other cases. What the settlement does do is remove TikTok from the first trial, and with it, the risk of internal documents and senior executives being questioned in public.

KGM’s case is the first of several “bellwether trials.” While the verdict will not formally bind other courts, it is expected to influence settlement strategies and judicial outcomes. More than 350 families and 250 school districts are part of the California proceedings.

The plaintiffs are seeking monetary damages and court orders requiring changes to platform design and safety standards.

Section 230, and why this case tests its limits

For years, lawsuits against social media companies ran into the same wall: Section 230 of the Communications Decency Act, a 1996 law that protects internet platforms from liability for content posted by users. Courts have interpreted it broadly, often dismissing cases at an early stage, even when platforms recommend or amplify harmful material.

This case survives because of a narrow but crucial distinction. Plaintiffs are not blaming the companies for what users posted. They are blaming them for how the platforms were built.

California Superior Court Judge Carolyn Kuhl ruled that jurors must decide whether the harm alleged was caused by third-party content, which would trigger Section 230 immunity, or by the companies’ own design choices. If it is the latter, the shield may not apply. This explains why Meta CEO Mark Zuckerberg and Instagram head Adam Mosseri are expected to testify, and why Snap and TikTok chose to settle instead.

What the companies say

Meta and Google reject the claim that their products are addictive or that they caused a youth mental health crisis. They argue that adolescent well-being is shaped by many forces, including family circumstances, academic pressure and economic stress, and that singling out social media oversimplifies a complex problem.

“The plaintiffs’ lawyers will try to paint an intentionally misleading picture of Meta with cherry-picked quotes,” Meta said in a recent blog post, adding that it has “consistently put teen safety ahead of growth.”

In court, the companies have leaned heavily on Section 230, arguing that they cannot be held liable for harm tied to content created by users, including viral “challenge videos.” YouTube has pointed to parental controls and age-appropriate products. Both companies say they have invested for years in safety tools and research.

Plaintiffs respond that many of those measures came only after internal studies flagged risks to young users. Some of those internal documents have been unsealed and are expected to be shown to jurors. According to plaintiffs’ lawyers, one internal message described Instagram as a “drug”. Another read, “lol, we’re basically pushers”. Meta disputes the context and relevance of those excerpts.

Why schools have struggled in court

Alongside individual plaintiffs, public school districts have argued that social media addiction has strained their budgets, forcing spending on counselling, discipline and repairs linked to online trends.

Courts have been sceptical. One reason is the economic loss rule, which bars recovery for purely financial harm not tied to personal injury or physical property damage. Judges have found that costs such as hiring counsellors or buying phone-locking pouches do not qualify.

Schools have also struggled to establish a legal duty. Applying established factors, courts have held that the link between a platform’s design and a student’s independent act, such as vandalising a bathroom during a viral challenge, is too remote to justify liability.

Public nuisance arguments have also failed. Courts have ruled that mental health harms are individual injuries, not interference with a shared public right like air or water. As a result, the individual injury cases, not the institutional ones, are carrying the legal experiment forward.