New Delhi, Aug. 22 -- The eight jurors seated in Oakland's federal courthouse this week are not being asked to decide whether teenagers have been harmed by Instagram and Facebook. That question was largely settled before the trial began, through prior verdicts and the internal Meta research now in the public record. The question before Judge Yvonne Gonzalez Rogers - and through her, before 29 state attorneys general who have spent years building this case - is whether a court can force a company to redesign the machine that caused the harm.

and more critically, what remedies she orders - could reshape how hundreds of millions of people, including an estimated 35 million American teenagers, experience the most-used social platforms in the...