A trial kicking off this week in Los Angeles will weigh one of the most fraught questions of the digital age: whether social media giants are responsible for harming children.

Meta Platforms, TikTok and YouTube will face courtroom scrutiny this week over allegations that their platforms are fueling a youth mental health crisis, as the national debate about kids’ screen time...

The lawsuit at the center of the jury trial getting underway Tuesday was filed by K.G.M., a 20-year-old who began using social media as a child and says she became addicted to the platforms, experienc...