School districts and state governments have filed lawsuits against major social media companies, including TikTok, Alphabet Inc., Meta, and Snap Inc. The plaintiffs argue that the companies' social media platforms harm children's mental health via addictive algorithms and harmful content.

Seattle public schools were the first to bring suit in January 2023, followed by the state of Arkansas in March 2023, a California school district in May 2023, multiple Maryland school districts in June 2023 and several Colorado school districts and the state of Utah in October 2023.

In May 2023, the US Surgeon General issued an advisory warning positing that social media poses “a profound risk of harm to the mental health and well-being of children” and that there is insufficient evidence “to determine if social media is sufficiently safe for children and adolescents.”

In late October 2023, 41 states and the District of Columbia sued Meta. Thirty-three states jointly filed a lawsuit in the US District Court for the Northern District of California; seven states (Tennessee, Massachusetts, Mississippi, New Hampshire, Oklahoma, Utah and Vermont) and the District of Columbia filed separate lawsuits in their local courts; and Florida filed a separate lawsuit in federal court. They allege that Meta intentionally designed its social media platforms to encourage addictive use and harm children’s mental health.

Federal cases filed across the country have been centralised in the US District Court for the Northern District of California as a multidistrict litigation for coordinated pretrial proceedings. Cases that are not resolved during these proceedings may later be returned to the federal courts in which they were originally filed.

In November 2023, the federal judge overseeing the multidistrict litigation dismissed a request made by social media companies to dismiss the lawsuits. The judge found the companies did owe their users a duty of care, although this duty did not extend to protecting from third-party harm on the platforms.

This multidistrict litigation has consolidated three types of claims: those brought by individuals, those brought by state attorney generals, and those brought by school districts. Each of these types of claims are planned to have separate test cases.

In June 2025, the judge overseeing the multidistrict litigation selected six school-district cases as bellwethers, or test cases, intended to help assess how juries may respond to the claims and inform potential settlements.

The first of these cases, brought by a Kentucky school district, was scheduled to go to trial in June 2026. However, in May 2026, Snap, YouTube, and TikTok and then Meta settled the case for a total of USD27m. The next school-district test case, brought by Tucson Unified School District, is scheduled for early 2027.

The first state attorney general test case is set to begin on 18 August 2026 over California, Colorado, Kentucky and New Jersey's claims.

The case brought by Tennessee attorney general against Meta in Tennessee state court, as part of the coordinated multistate effort by several attorneys general, began on 20 July 2026.

Separate proceedings are also ongoing in state court in California over similar allegations.

There is also an ongoing case against Meta in New Mexico state court over allegations that it failed to protect children from sexual exploitation.