A court just ruled that tech addiction is real—and dangerous. It could be Meta and YouTube’s Big Tobacco moment

A Los Angeles jury has sided with a young woman known as Kaley or KGM in a landmark case, ruling that the “addictive design” of Instagram, Facebook, and YouTube helped fuel her serious mental health problems. The closely watched bellwether case against the platforms’ parents, Alphabet’s ‌Google and Meta, could set a precedent in thousands of similar lawsuits and force Silicon Valley to rethink the features that keep users endlessly scrolling.

After more than 40 hours of deliberation...