Mark Zuckerberg and Instagram chief Adam Mosseri Meta
Mark Zuckerberg and Instagram chief Adam Mosseri are set to testify in the six-week Oakland trial over how teens use social apps Anthony Quintano/Wikimedia Commons

A bipartisan coalition of 29 US states opened a $200 billion (£148 billion) trial against Meta in Oakland on Tuesday, citing an internal study called 'The Young Ones Are The Best Ones' as proof the firm designed Instagram to addict children.

Opening arguments began on 18 August at the Ronald V. Dellums Federal Building before US District Judge Yvonne Gonzalez Rogers. California, Colorado, Kentucky, and New Jersey are leading the group, with all 29 states claiming Meta broke the Children's Online Privacy Protection Act (COPPA) by collecting data on users under 13 without parental consent.

California Attorney General Rob Bonta, who attended the opening, has said Meta 'designed a dangerous product for young users, knew it to be dangerous, and then lied' about the risks.

What the 'Young Ones' Memo Revealed

A deputy California attorney general, Megan O'Neill, told the eight-person advisory jury that Meta set out to 'hook the users, hold them for as long as they can, harvest their data, and then hide the truth from the public'. She pointed to a company study titled 'Long Term Retention: The Young Ones Are The Best Ones', which found that the earlier a child joins, the longer they stay and the more money they generate.

The research examined tweens, roughly 10 to 12 years old. Meta claimed to prioritise safety over profit, O'Neill said, but 'time and again profits won'. Kentucky Attorney General Russell Coleman called it the largest consumer protection case in US history and compared it to past tobacco and opioid settlements.

The Changes That Could Reshape Your Child's Apps

The overlooked stakes sit in the remedies, not the payout. The four lead states want Meta to strip the like button and infinite scroll for young users, add daily time limits, and enforce tighter, robust verification barriers to stop children under 13 from bypassing account walls.

If the judge agrees, the version of Instagram and Facebook on a teenager's phone could soon look and behave very differently. Parents following the case have a direct stake in that decision, because a ruling for the states would apply to features millions of American teenagers use every day.

The $200 Billion Fight Over Damages

The states told the court last week they are seeking about $200 billion, roughly three years of Meta's after-tax profit. Meta has argued in filings the figure could reach $1.4 trillion (£1.03 trillion), close to its entire market value, a number the states dismissed as chosen 'for shock value'.

Meta attorney Paul Schmidt told jurors the company 'strongly disagrees' with the claims, called the internal messages 'loose language', and questioned whether social media addiction is scientifically possible.

Zuckerberg To Testify as Wave of Cases Builds

Chief Executive Mark Zuckerberg and Instagram head Adam Mosseri are expected to testify during a trial set to run about six weeks, with a final judicial ruling expected by early October. Meta says the claims are unsubstantiated and points to teen safeguards including private default accounts and a one-hour Instagram reminder timer.

The Oakland case is the first multi-state federal coalition lawsuit to reach a jury and follows a New Mexico ruling this month that ordered Meta to overhaul its teen protections.

Similar suits against TikTok, Snapchat, and Google's YouTube are moving through the courts, part of more than 3,000 consolidated cases nationwide.