Meta Trial: Mark Zuckerberg Told 9-Year-Olds 'Lied' About Their Age — Internal Docs Show Meta Tracked Tween Retention Rates

Mark Zuckerberg knew children were lying about their ages to use Instagram. What he didn't explain is why Meta was tracking how often they came back.

The Meta chief executive took the stand Wednesday in a Los Angeles courtroom, facing a jury for the first time over claims that Instagram was designed to hook young users. But the real bombshell wasn't his testimony. It was buried in Meta's own internal files.

The Documents Meta Didn't Want You to See

A 2020 internal review showed that 11-year-olds were four times more likely to keep returning to Facebook than older users. Instagram's minimum sign-up age is 13.

'People who join Facebook at 11 years old?' plaintiff's lawyer Mark Lanier asked. 'I thought y'all didn't have any of those?'

Zuckerberg didn't have a good answer.

Lanier then pulled up 2015 documents showing roughly 30% of American 10-to-12-year-olds were on Instagram. Another file revealed the company's goal of increasing how long 10-year-olds spend on the app. A 2018 internal memo put it bluntly: 'If we wanna win big with teens, we must bring them in as tweens.'

'I don't remember the context of this email from more than 10 years ago,' Zuckerberg responded.

40 Minutes Wasn't Enough

Here's what parents should know. Instagram's internal engagement target was 40 minutes daily in 2023. The company planned to push that to 46 minutes by 2026.

The plaintiff, identified as KGM, started using social media at age six. She was on Instagram by age nine. Court documents show she once spent more than 16 hours on the platform in a single day. Her mother tried using third-party software to block access. It didn't work.

'You expect a 9-year-old to read all of the fine print?' Lanier asked Zuckerberg. 'That's your basis for swearing under oath that children under 13 are not allowed?'

Instagram didn't even require birthdates at sign-up until late 2019.

Then came the trial's most striking moment. Five lawyers unspooled a roughly 20-foot collage — hundreds of selfies KGM had posted as a child. Lanier asked Zuckerberg if her account had ever been flagged for this level of use.

The Meta CEO didn't say.

Two Companies Already Walked Away

TikTok and Snap both settled before trial. The terms remain confidential, but the message is clear: they saw liability they couldn't defend.

That leaves Meta and YouTube as the only defendants standing. This case is a bellwether — a test run tied to some 1,600 similar lawsuits from families and school districts across the US. How this jury decides will shape settlement talks for every pending case.

What Happens if Meta Loses

A verdict against the company could force changes to how every child uses the internet. Think of the removal of infinite scroll. Beauty filters banned for minors. Algorithmic recommendations scrapped for young users.

Matt Bergman, whose Social Media Victims Law Centre represents about 750 plaintiffs, called Wednesday's testimony 'more than a legal milestone — it is a moment that families across this country have been waiting for.'

Meta disputes the claims. A company spokesperson said they're 'confident the evidence will show our longstanding commitment to supporting young people.'

But those internal documents tell a different story. Meta wasn't just aware that children were on its platforms. The company was measuring how sticky its product was for users who weren't supposed to be there — then setting goals to make it stickier.