“Social media platforms Instagram and YouTube have a design defect which means they are addictive, a jury in the United States has ruled.”

“The Los Angeles jury took nearly nine days to reach its verdict in the landmark case brought by a woman known as KGM against social media platforms.”

“It awarded US$3 million in damages, with Meta (owner of Instagram) being 70% responsible and Google (owner of YouTube) 30%.”

“Both TikTok and Snap settled on confidential terms before the six-week trial commenced.”

“This is Meta’s second big loss in the US courts this week, with a New Mexico jury finding the company guilty on March 24 of concealing information about the risks of child sexual exploitation and the harmful effects of its platforms on children’s mental health.”

“KGM’s case is the first of its kind, but won’t be the last: it is one of more than 20 'bellwether' trials due to go to court soon.”

“The verdict is set to have far reaching ripple effects. It could be big tech’s big tobacco moment, with thousands more similar cases waiting in the wings.”

“KGM – now 20 years old – said she began using YouTube at age six and Instagram at age nine, and allegedly developed compulsive use patterns, including up to 16 hours in a single day on Instagram.”

“Her case argued that Meta and YouTube made deliberate design choices – for example, 'infinite scroll' – to make their platforms more addictive to children in order to boost profits.”

“Lanier cited an internal Meta study called 'Project Myst'. This allegedly found that children who had experienced 'adverse effects' were most likely to get addicted to Instagram, and that parents were powerless to stop the addiction.”

“The verdict demonstrates the limitations of Section 230 protections for big tech companies.”

“Meta and Google have stated they plan to appeal the verdict.”

“KGM’s case paves the way for other actions seeking damages from social media platforms for the effects of addiction.”

“A New Mexico jury found Meta guilty of false statements and unconscionable trade practices, resulting in a $375 million penalty.”

“Meta argued KGM faced significant challenges before she ever used social media, and that the evidence did not support reducing a lifetime of hardship to a single factor.”

“This was one of the first cases against big tech which was a jury trial – something companies have previously been keen to avoid.”

“The companies centred part of their defence on Section 230 protections, arguing they cannot be held liable for content posted on their platforms.”

“The jury heard that Meta’s internal communications compared the platform’s effects to pushing drugs and gambling. The jury found this internal awareness was the kind of corporate knowledge that supports liability.”

“YouTube’s lawyer argued there was not a single mention of an addiction to YouTube in KGM’s medical records.”

“Google paid more than US$2 million (A$2.8 million) to the Department of Justice to avoid a jury trial in its antitrust case.”

“A YouTube memo reportedly described 'viewer addiction' as a goal, and an Instagram employee wrote the company was staffed by 'basically pushers'.”

“Meta’s chief executive Mark Zuckerberg gave evidence for the defence: 'I’m not trying to maximise the amount of time people spend every month.'”