After a grueling seven weeks of court proceedings and more than 40 hours of tense deliberations across nine days in one of the country’s most closely watched civil trials, jurors handed down a landmark decision in Los Angeles County Superior Court on Wednesday, finding Instagram and YouTube responsible for the suffering of a Chico, Calif., woman who charged the platforms were built to addict young users. Kaley G.M., the 20-year-old plaintiff, who testified in February, arrived in court just befo...