Nardine Saad,

Regan Morrisand

Kali Hays

A Los Angeles jury has handed down an unprecedented win for a young woman who sued Meta and Google over her childhood addiction to social media.

A panel of jurors found Meta and Google intentionally built addictive social media platforms that harmed the mental health of a 20-year old woman, known as Kaley.

The result will likely influence hundreds of similar cases now winding their way through the US courts.

Lawyers for Meta argued that while Kaley had suffered in her life, her use of Instagram - which Meta owns along with Facebook and WhatsApp - did not cause or meaningfully contribute to those struggles.

After a trial that lasted about five weeks, jurors found Meta to be 70% responsible for the plaintiff's harm - and YouTube was 30% to blame.

In a statement, Meta said: "We respectfully disagree with the verdict and are evaluating our legal options."

During his first-ever appearance before a jury in February, Meta's chairman and chief executive, Mark Zuckerberg, relied on his company's longstanding policy of not allowing users under the age of 13 on any of its platforms.

When presented with internal research and documents showing that Meta knew young children were in fact using its platforms, Zuckerberg said he "always wished" for faster progress to identify users under 13. He insisted the company had reached the "right place over time".

While Google, as the owner of YouTube, was also a defendant in the case, most of the trial proceedings focused on Instagram and Meta.

Snap and TikTok were also initially defendants, but both companies reached undisclosed settlements with Kaley prior to trial.