The verdict lands just days after a separate jury found Meta liable for enabling child exploitation in another case, establishing what legal experts say is a clear pattern of judicial accountability for social media companies' treatment of young users.

During the trial, the plaintiff known as K.G.M. testified that every notification made it harder to stop logging in, describing how the platforms' engagement-maximising designs created what amounted to a digital trap. Meta faces the larger share of the fine at 70 per cent, reflecting the jury's assessment that its platforms bore greater responsibility.

The verdict's implications extend well beyond the United States. Analysts note that the ruling could ripple through social media markets worldwide, potentially emboldening regulators in Europe, Southeast Asia, and Latin America who have been weighing their own restrictions on addictive platform design.