In 1994, forty-odd American states did something that seemed almost impossible: they sued Big Tobacco and, eventually, won a settlement larger than any industry had ever paid. Thirty years on, smoking has risen across the developing world, the tobacco companies remain profitable, and the global market for cigarettes is worth nearly one trillion dollars. That uncomfortable history now hangs over a courthouse in Oakland, California, where, on a Tuesday in August, twenty-nine US states opened a major trial against Meta — the parent company of Facebook and Instagram — alleging that it deliberately engineered an addictive product and then aimed it squarely at children. The case does not arrive without precedent.

Earlier this year, a Los Angeles jury found Meta and YouTube liable for designing a product whose addictive properties had caused measurable harm to the mental health of a single young claimant, awarding her six million dollars. That verdict cracked open the door for the current, far larger action. Almost simultaneously, Meta was ordered to pay $942 million in a separate New Mexico case, which had centred on whether the company knew about — and failed to prevent — child sexual exploitation on its platforms. Where New Mexico focused on content, this new trial focuses on architecture: the recommendation algorithm itself, and the choices buried inside it.

The financial stakes are difficult to overstate. The states' attorneys general are seeking $200 billion in damages — roughly equal to Meta's annual revenue. Meta's own court filing estimates its total exposure at $1.4 trillion, a figure the presiding judge has already dismissed as unreasonable.

Kate Winick, an analyst at Forrester, has described the trial as "potentially the end of social media as we know it," arguing that even a partial ruling against Meta could significantly reduce platform usage over the long term.