A Los Angeles jury has ruled that social media giants Meta and Google-owned Youtube are guilty of negligent platform design that resulted in harm to a young user's mental health.

The ruling came after several days of deliberation in a personal injury lawsuit that industry experts say will have rippling effects on Big Tech.

The jury agreed with the plaintiff that the platforms' design features were a "substantial factor" in causing mental health-related harms and that company leaders knew their products were dangerously addictive. The companies have been ordered to split compensatory damages of $3 million, with Meta paying 70 percent and YouTube 30 percent. Meta says it is exploring legal options to appeal the decision.

"Today, a jury saw the truth and held Meta and Google accountable for designing products that addict and harm children," said court-appointed plaintiff counsel Lexi Hazam and Previn Warren, in a statement following the decision. "Top tech executives took the stand, and their own internal documents were put before a jury, revealing that company leadership knew their platforms were hurting kids and repeatedly chose profits over children's safety. This verdict sends an unmistakable message that no company is above accountability when it comes to our children." 

Instagram CEO Adam Mosseri and Meta CEO Mark Zuckerberg both testified in front of the jury last month. Other social media platforms were also named in the lawsuit, brought forth by a young user referred to as K.G.M and her mother. K.G.M. accused the platforms of knowingly investing in site features that led to addictive behavior, self-harm, and suicidal thoughts, even after safety warnings were flagged by internal employees — it's the first of a consolidated group of lawsuits filed by more than 1,600 plaintiffs, known as a watershed case. TikTok and Snapchat both settled with K.G.M. prior to the jury trial.

"Social media giants would never have faced trial if they had prioritized kids' safety over engagement. Instead, they buried their own research showing children were being harmed, and used kids and society as guinea pigs in massive, uncontrolled, and wildly profitable experiments. Now, executives are being held to account," wrote James P. Steyer, founder and CEO of child safety nonprofit Common Sense Media.

Hours before the K.G.M decision was announced, a different jury announced another guilty verdict for Meta, which ordered the tech giant to pay $375 million in damages for misleading users about its platform's safety features and endangering young users. The case was brought forth by New Mexico Attorney General Raúl Torrez, amid a wave of similar state-level lawsuits against social media platforms over the last few years.