YouTube told a Los Angeles jury it is an entertainment platform, not addictive social media, in a landmark US trial against tech giants. Alongside Meta, YouTube faces allegations that its design harmed a 20-year-old plaintiff who began using the platform at age six. The defense argued she was not addicted and said content quality—not engineered addiction—drives engagement. The case, viewed as a bellwether, could influence hundreds of similar lawsuits accusing social media firms of causing depression and other mental health harms in young users.