New Delhi, Aug. 19 -- Meta is under scrutiny over its alleged cover-up of internal research, showing teenagers are getting addicted to its platforms, as a lawsuit filed by 29 US states went to trial on Tuesday.

Lawyers representing the attorneys general argued that while safeguarding children's health and well-being is a shared responsibility, "Meta didn't do its share."

Megan O'Neill, California's deputy attorney general, told jurors they would see internal documents and hear witnesses' testimonies regarding how Meta allegedly tried to cover up research into social media addiction.

One document said, "the young ones are the best ones", while another said, "Teens are hooked despite how it makes them feel. Instagram is addictive," a rep...