Mark Lanier, photographed in Oxfordshire in May this year. Photograph: Gareth Iwan Jones/The Guardian View image in fullscreen Mark Lanier, photographed in Oxfordshire in May this year. Photograph: Gareth Iwan Jones/The Guardian Social media Interview ‘This was a righteous case. A holy war’: the lawyer who took on Meta and Google – and won Jenny Kleeman 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?
Sun 12 Jul 2026 13.00 CEST Last modified on Sun 12 Jul 2026 23.55 CEST Share Prefer the Guardian on Google W hen 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.
But there were specific reasons why the prosecution was deeply disturbed to see Meta Ray-Bans in court. “We had fought hard for an anonymous jury. We didn’t want the names disclosed in a way where Google could go pull up their Gmails, where Meta could go pull up their Facebook accounts,” Lanier tells me in his warm Texas drawl. “Then Zuckerberg shows up with security guards wearing Meta glasses. They can easily [use photos from the glasses and] do facial identification and figure out exactly who the jurors are.” This was not product placement, Lanier says – it was the deployment of the most relentless form of digital surveillance the world has ever known.
The prosecution appealed to the judge , pointing out that Zuckerberg’s entourage was breaking rules that forbade cameras in the courtroom. “The judge made them swear that they hadn’t taken any pictures.” Lanier says. “And then they took the glasses off.”
The case of KGM v Meta et al was always going to be as hi-tech as it was high stakes. KGM – also known by her first name, Kaley – claimed that an addiction to social media that had begun with YouTube at age six and Instagram at age nine had caused her to develop body dysmorphia, anxiety and depression. (Snapchat and TikTok, named in Kaley’s original complaint, had settled out of court for an undisclosed sum before the trial began.) Lanier’s team had to convince the jury that Meta and Google had engineered their products to be addictive. It was a test case that could blaze a trail for thousands more to come.
“I’d never been in court before,” Kaley, now 20, tells me in her first newspaper interview. “Seeing all those people, and having all their eyes on me, was very overwhelming.”
View image in fullscreen Mark Zucke…