After more than 40 hours of deliberation across nine days—including testimony from KGM as well as from Meta CEO Mark Zuckerberg and other tech leaders—California jurors decided Meta and YouTube were negligent in the design or operation of their platforms, and awarded the plaintiff, a 20-year-old woman who says her social media addiction exacerbated her mental health struggles, $3 million in damages.

The multimillion-dollar verdict will grow, as the jury will decide whether the companies acted with malice or fraud. They will hear new evidence shortly and head back into the deliberation room to decide on punitive damages. Meta and Google-owned YouTube were the two remaining defendants in the case after TikTok and Snap each settled before the trial began.

“We respectfully disagree with the verdict and are evaluating our legal options,” a Meta spokesperson said when reached for comment Wednesday. 

A spokesperson for YouTube parent company Google said the company also disagrees with the verdict and plans to appeal. “This case misunderstands YouTube, which is a responsibly built streaming platform, not a social media site,” the spokesperson said.

The decision also puts legal weight behind a term Big Tech has spent years trying to dismiss: tech addiction. As I reported in Fortune this week, and for the upcoming issue of Fortune Magazine, the intense debate about how harmfully addictive modern tech can be has escalated lately thanks to a slew of landmark legal cases against Meta, YouTube, TikTok, and Snap. 

At a dedicated tech addiction rehab center outside of Seattle—one of very few such clinics in the U.S. or anywhere in the world—I met client Sarah Hill. The 21-year-old’s parents had flown her from Alabama to reSTART, a residential treatment program for digital overuse that treats compulsive tech use as a danger on par with alcohol or drugs. At the program, which costs around $1,000 a day, clients must abstain from smartphones, gaming, social media, and other technologies—often for months, and undergo intensive therapy sessions.

Hill told me that the situation got to a crisis point when she had spent so many nights holed up in her room talking to an AI chatbot on her phone that she fell behind in her college classes, lied to her parents, and ultimately failed out. “The last thing I saw was my mom resting her elbows on the counter and just crying,” she recalls. “That was the worst thing I ever saw.” On her first tech-free day at reSTART, Hill told me, she lay down on her bed and cried.

Hill is far from alone. reSTART cofounder Cosette Rae says she has treated around a thousand clients since opening the center nearly two decades ago, and spoken with many thousands more. She and cofounder Hilarie Cash launched reSTART in 2009 because they realized that there was nowhere else for those struggling with problematic tech use to go.

Rae’s patients aren’t simply dealing with bad habits, she says. They’re struggling with the fact that you can’t quit tech the way you might quit a substance. “When it comes to technology, it’s everywhere,” she says. “So you’re constantly being in front of it and having to say no.”

Scientists like Stanford psychiatrist Anna Lembke, who testified on behalf of the plaintiff in the Meta and YouTube case, say that’s not just anecdotal. Compulsive scrolling and gaming tap the same reward circuitry as drugs, with quick dopamine hits training users to seek the next small “win.” Over time, repeated bursts of stimulation can desensitize those pathways and weaken the prefrontal cortex, which governs planning and self-control, making it harder to cut back even as school, work, or relationships suffer. Brain imaging studies of people with internet gaming or social media disorders show changes similar to those seen in gambling addiction.

Meta and YouTube have long argued that there’s no clear scientific proof their products cause that harm. Tech addiction isn’t recognized as a formal diagnosis in the Diagnostic and Statistical Manual of Mental Disorders; only “internet gaming disorder” appears as a condition warranting more study. Some researchers worry that calling heavy use “addiction” can make people feel more helpless, not less.

But critics have long said that these products are designed to foster addiction. “These companies are in the business of attention,” the former tech investor and author of Zucked: Waking Up to the Facebook Catastrophe, Roger McNamee, told me, weeks before today’s verdict. “Once they had attention, they were in the business of controlling the choices available to people in order to influence their behavior in ways that were profitable for the platform. That culture and that business model were guaranteed to produce lots of harm.”

Indeed, some watching the Los Angeles and other lawsuits move forward have anticipated a “Big Tobacco moment”—a reference to the 1990s lawsuits against tobacco companies that proved they were aware of the addictive nature of nicotine and the health dangers of smoking, and led to massive damages paid.

NYU professor and podcaster Scott Galloway, also speaking before the verdict, was even more blunt about what the attention race has meant for young people. “I don’t think [Big Tech] set out in their business plans to depress global youth,” he says. “I think their algorithms discovered that rage, self-esteem, and funny cat videos just keep people online.”

For Hill, the stakes are personal, not theoretical. She has now transitioned to an apartment owned by reSTART and carries a basic “dumb” phone with no apps or games. She still catches herself slipping into old patterns—like mindlessly scrolling through new screen backgrounds—but says something fundamental has shifted. 

“After making so many mistakes, I’m finally putting a foot down and saying, ‘I want to get out of this endless cycle,’” she says. “I need to do something to better myself and my life.”

This article used reporting from the Associated Press.