A federal appeals court has refused to dismiss thousands of lawsuits against Meta, Google, TikTok, and Snapchat, allowing complaints alleging that the platforms were deliberately designed to be addictive to young users to proceed. The cases, consolidated in federal multidistrict litigation, represent one of the most expansive legal challenges to the social media industry over its products' effects on minors.

The Ninth U.S. Circuit Court of Appeals rejected an appeal by Meta and TikTok that sought to overturn a lower court ruling requiring the companies to face more than 3,000 lawsuits filed in federal court. The appellate panel ruled that the companies had appealed too early in the litigation process.

The social media companies argued that Section 230 of the Communications Decency Act of 1996 — which generally shields online platforms from liability for content posted by their users — also bars lawsuits alleging they failed to warn the public about the addictive design of their platforms. Section 230 has historically protected numerous companies from lawsuits related to user-posted content and is widely regarded as a foundational legal shield for the modern internet economy.

Most appeals are filed after a case has reached a ruling or verdict, but the companies contended they should not have to wait until the litigation concludes to challenge the lower court's rejection of their immunity defense.

However, the court ruled that the companies cannot invoke Section 230 to dismiss lawsuits at this stage, holding that it can only be used as a defense against liability claims — not as grounds for premature dismissal. The statute "merely provides a defense to liability — not immunity from suit," Judge Jacqueline Nguyen wrote in the ruling.

The decision clears the way for lawsuits alleging that social media companies designed their platforms to encourage addictive behavior, failed to verify users' ages, and did not adequately block harmful content. The claims center on product design choices rather than third-party posts, a distinction plaintiffs argue places their cases outside Section 230's scope.

The appellate panel also denied Meta's attempt to postpone a trial scheduled to begin on Wednesday in a lawsuit brought by 29 state attorneys general. That lawsuit accuses the company of illegally collecting and using children's data, designing its social media platforms to addict young users, and misleading consumers about child safety on the platforms. Meta had argued the trial could not move forward while the appeal was pending.

Fox Business reached out to Meta and TikTok for comment.

Attorneys representing thousands of school districts and individuals suing Meta and other tech firms in federal court said in a statement that the ruling would allow the states' trial to proceed, as well as a trial over claims brought by school districts scheduled for February.

"A trial is how the public finds out what Meta knew about its products' impact on children, when it knew it, and what it chose to do with that knowledge," the attorneys said. "Meta has fought to keep that evidence from the public."

The ruling follows a decision by a New Mexico judge last week finding that Meta had created a public nuisance in the state. The judge ordered the company to pay $567 million into a teenage mental health fund and to adopt youth-safety measures.

In March, a jury in California ruled against Meta and Google's YouTube, while a jury in New Mexico also ruled against Meta on child safety risks.

The litigation unfolds alongside a broader push by lawmakers and regulators to address online platforms' interactions with minors. Several states have enacted laws requiring parental consent for underage users or restricting addictive design features, and members of Congress have proposed federal reforms including the Kids Online Safety Act. The upcoming trials are expected to be among the first major tests of whether evidence and testimony in these cases can establish that platform design decisions caused measurable harm to young users.

Reuters contributed to this report.