On Wednesday, Meta agreed to pay up to $17.1 billion to states to settle claims it harmed young users with its addictive platforms. The settlement was a major capitulation by Meta, which along with YouTube, Snap and TikTok have faced a series of trials this year in which lawyers have accused the companies of designing their platforms for compulsive use, like cigarettes, taking a page from the playbook used against Big Tobacco in the 1990s. And they’ve argued that the companies deceive the public by marketing their products as safe. Thousands of individuals, school districts and state attorneys general have filed similar lawsuits. The settlement could signal an inflection point for a social media industry that has largely escaped regulatory scrutiny over the harms its products have caused children.

These cases test the argument that social media was built to be addictive, like cigarettes or casino slot machines. The lawsuits claim that features like infinite scrolling, algorithmic recommendations, notifications and videos that play automatically lead to compulsive use. The plaintiffs contend that the resulting addiction has led to problems like depression, anxiety, eating disorders and self-harm, including suicide. Cases filed by individual plaintiffs tested a novel legal theory, claiming the companies caused personal injury through defective products. The states have cited consumer protection laws and child privacy law violations.

The first plaintiff was a 20-year-old woman from California identified as K.G.M. in California Superior Court in Los Angeles County. K.G.M. created a YouTube account at age 8, then joined Instagram, which is owned by Meta, at 9. In her lawsuit, she claimed she became addicted to the social media sites as a child and experienced anxiety, depression and body-image issues. In March, all but two of the jurors determined that Meta and YouTube were negligent, and she was awarded $6 million.

Judges have bundled some of the strongest cases to act as bellwethers. A separate set of federal cases will go to trial in Oakland, Calif., at the U.S. District Court of Northern California. The states’ settlement effectively ends the first federal bellwether trial that began last week, where California, Colorado, Kentucky and New Jersey were seeking roughly $200 billion. School districts are also scheduled to go to trial in Oakland. Separately, a New Mexico judge ordered Meta to pay penalties totaling nearly $1 billion.