Meta settled claims on Friday, Oct. 30, brought by a teenage plaintiff who alleged that Instagram and Facebook were addictive and damaged her mental health, her attorneys said. The plaintiff, identified in court records as K.D.B., reached the agreement a day after Meta settled similar claims brought by another teenager, S.J. Neither settlement’s terms were disclosed.

TikTok and YouTube had already resolved claims from both teenagers in the weeks before trial. Those agreements and Meta’s settlements leave Snapchat owner Snap Inc. as the sole remaining defendant. Jury selection began this week in Los Angeles, with opening arguments scheduled for Nov. 4. Emily Jeffcott, trial counsel for K.D.B., said her team remained committed to improving children’s safety on social media and holding technology companies accountable.

The teenagers’ lawsuit alleges that Snap developed features intended to increase the amount of time young people spend using Snapchat. It identifies Snapstreaks, Snapscores and filters as features that can encourage compulsive use, allegedly contributing to severe mental and physical health problems, including self-harm.

The trial is the fourth bellwether proceeding in consolidated litigation against Instagram, YouTube, TikTok and Snap. The cases involve more than 1,600 plaintiffs, including over 350 families and over 250 school districts. They accuse the companies of knowingly creating addictive products that harm young users’ mental health. Social media companies have historically received broad protection under Section 230, a provision added to the Communications Act of 1934 that shields internet companies from liability for content posted by users.

Meta has repeatedly rejected allegations that its apps are intentionally harmful and addictive for young people. In a separate Los Angeles trial in March, however, a jury found Meta and Google’s YouTube negligent in how they designed or operated their platforms. Jurors concluded that the negligence substantially contributed to harm suffered by a plaintiff identified as K.G.M. and that the companies had not adequately warned users about the dangers of Instagram and YouTube.

That jury awarded K.G.M., now 20, $3 million in compensatory damages. It assigned Meta 70% of the responsibility for her harm and YouTube 30%. In August, Meta also agreed to an approximately $18 billion settlement of a broad social media addiction lawsuit involving California and other states. A court filing identified 29 states as plaintiffs and said Meta denied the allegations and any liability.

A Meta spokesperson told NBC News on Friday that the company would continue defending itself in court and stood behind its record. The spokesperson cited more than a decade of protections for teenagers and described an agreement with 52 bipartisan attorneys general that includes strict time limits, no nighttime access and no notifications during school hours.

Snap, responding Friday with a statement issued earlier in the week, said Snapchat opens to a camera rather than a feed or rankings of other people’s posts. The company pointed to safeguards, safety tools and educational resources, and said it expected the evidence to support its position that it had prioritized its community. Snap also disputed the allegations’ portrayal of the plaintiffs’ experiences and the platform’s design.