‘This was a righteous case. A holy war’: the lawyer who took on Meta and Google – and won

When Mark Lanier and his young client Kaley faced the tech giants in an LA courtroom earlier this year, it seemed a bigger battle than David v Goliath. But they scored a landmark victory, proving that the social media giants had created ‘addiction machines’ that harmed mental health. How did they pull it off?

When Mark Zuckerberg walked into a Los Angeles courtroom on 18 February flanked by an entourage bedecked in Meta Ray-Bans, some people laughed. If this was an attempt at product placement for the company’s newest range of smart glasses, it was jarringly ill-judged: Zuckerberg was about to testify before a jury in a landmark lawsuit that sought to prove that Instagram and YouTube are addictive by design, and he had passed a throng of bereaved parents on his way into the courthouse. But the prosecution team, led by Mark Lanier, were not laughing.

This was a serious trial. For the first time, the most powerful names in social media were being held to account for the inherent design of their platforms, rather than the content hosted on them. They were accused of deliberately and maliciously building products that keep children hooked, with disastrous consequences for the mental wellbeing of young people. It was a landmark case – a big tobacco moment for big tech.