STORY: A California state court case over whether Instagram and YouTube harmed a woman’s mental health through addictive app design kicks off on Monday (February 9).It’s seen as a test of whether Big Tech platforms can be held liable for harming kids.The 20-year-old woman identified as K.G.M. filed the lawsuit against Instagram parent company Meta and Alphabet’s Google, which owns YouTube.According to court filings, she says the attention-grabbing design of the platforms got her addicted to them at a young age.She alleges the apps fueled her depression and suicidal thoughts, and wants to hold the companies liable.A verdict against the tech firms could lead the way for similar cases in state court.And shake the industry’s longstanding U.S. legal defense against claims of user harm.Google, Meta, TikTok and Snap face thousands of lawsuits in California. Meta CEO Mark Zuckerberg is expected to be called as a witness at the trial.TikTok and Snap settled with K.G.M. before the trial.