A jury has found Meta and YouTube liable in a first-of-its-kind lawsuit that aimed to hold social media platforms responsible for harm to children using their services.

Meta and YouTube must pay millions in damages to a 20-year-old woman after a jury decided the social media giant and video streamer designed their platforms to hook young users without concern for their well being.

The California jury’s decision Wednesday in a first-of-its-kind lawsuit could influence the outcome of thousands of similar lawsuits accusing social media companies of deliberately causing harm.

The plaintiff, known by her initials KGM, testified at trial that she became addicted to social media as a child and that this addiction exacerbated her mental health struggles. After more than 40 hours of deliberations, a majority of jurors agreed and awarded her $3 million in damages.