Instagram and YouTube have been accused of "engineer[ing] addiction in children's brains", in the opening statements of a landmark social media trial taking place in LA.
Mark Lanier, representing plaintiffs who accuse social media companies of developing harmful and addictive platforms, described the case as being "as easy as ABC", which he said stands for "addicting the brains of children."
This is the first of a number of "bellwether" lawsuits, ie test cases, with lawyers considering the testimonies of more than 1,500 people when launching the action.
Both TikTok and Snapchat settled out of court in the first lawsuit but will be involved in subsequent trials.
If the social media companies lose, they'll need to pay compensation but could also be forced to change the way they work.
Read more: Social media goes on trial in LA - here's what you need to know
Mr Lanier called Meta and Google "two of the richest corporations in history" that have "engineered addiction in children's brains".
Meta's lawyer, Paul Schmidt, spoke of the disagreement within the scientific community over social media addiction, with some believing it doesn't exist or that addiction is not the most appropriate way to describe heavy social media use.
He also spoke about the 20-year-old plaintiff, known as KGM, and her mental health struggles.
Her lawyer, Mr Lanier, said she started using YouTube at age 6 and Instagram at age 9. Before she finished primary school, she had posted 284 videos on YouTube.
She says she became addicted to social media, which caused her anxiety, depression and body image issues.
However, Meta's lawyer, Mr Schmidt, argued her mental health issues were caused by other things going on in her life.
"If you took Instagram away, would she have experienced those same struggles?" he asked the jury, telling them to consider the question throughout the trial, which is expected to last around eight weeks.
Mr Lanier told the jury that Google and Meta "deliberately designed their products to hook users and keep them coming back, not by accident [but] by design, because addiction is profitable".
He pointed out three features he said were designed to make social media addictive:
• "The endless ride", or infinite scrolling
• The "chemical high five", or the like button, which he said "caters to a minor's craving for social validation"
• The "fun house mirror", or body image filters, which he said means a young person looks at the screen and sees a "perfect version of herself that doesn't exist"
Meta chief executive Mark Zuckerberg is among the tech execs expected to testify, along with Adam Mosseri, head of Instagram.
In a blog post, Meta said this kind of legal action against them "oversimplifies" the "complex issue" of teenage mental health.
"Narrowing the challenges faced by teens to a single factor ignores the scientific research and the many stressors impacting young people today, like academic pressure, school safety, socio-economic challenges, and substance abuse," said the post.
Read more from Sky News:
Face of a 'vampire' revealed
This AI just passed the 'vending machine test'
In a statement to Sky News, Google also rebuffed the trial's central allegations.
"Providing young people with a safer, healthier experience has always been core to our work," said Google spokesperson Jose Castaneda.
"In collaboration with youth, mental health and parenting experts, we built services and policies to provide young people with age-appropriate experiences, and parents with robust controls.
"The allegations in these complaints are simply not true."
(c) Sky News 2026: Instagram and YouTube 'engineer addiction' in young people, landmark trial hears
Beavers released at two sites in Somerset to help 'restore nature'
Instagram, TikTok and Facebook posts by users promoting weight-loss jabs banned as 'ads' for the first time
Claude Opus 4.6: This AI just passed the 'vending machine test' - and we may want to be worried about how it did
Parents admit they have no idea what their children look at on their smartphones
