Plaintiff Rests, Defense Begins Presenting Evidence in Social Media Addiction Trial

In the case of a California woman, now 20, allegedly harmed by social media, defense attorneys for Meta and Instagram present two witnesses from her school.

Meta Platforms CEO Mark Zuckerberg testifies before Los Angeles Superior Court Judge Carolyn Kuhl at a trial in a key test case accusing Meta and Google's YouTube of harming kids' mental health through addictive platforms, in Los Angeles, Calif., on Feb. 18, 2026 in a courtroom sketch. Reuters/Mona Edwards

LOS ANGELES—After four weeks, attorneys representing the plaintiff in a landmark jury trial in Los Angeles Superior Court—considering whether two of the world’s largest social media companies may be held liable for alleged harms to children resulting from “addictive” design features—rested their case on March 6.

The jury has heard testimony from Meta CEO Mark Zuckerberg, Instagram head Adam Mosseri, and YouTube Vice President of Engineering Cristos Goodrow, as well as addiction experts, whistleblowers, and the plaintiff herself, a 20-year-old California woman identified in court documents as “K.G.M” or “Kaley G.M.”