In what can be considered a landmark trial that could shape how social media platforms operate for years. Meta chief executive Zuckerberg testified in Los Angeles on accusations that Instagram is designed to be harmful to young users.

According to reports, Zuckerberg faced a jury as KGM, the 20-year-old plaintiff, and her mother alleged that her obsessive use of platforms, including Instagram and YouTube, from age six, exposed her to harmful content and worsened depression and suicidal thoughts, BBC News reported.

Zuckerberg faced questions about Meta documents, emails from about a decade ago that referenced company goals, including increasing time spent.

Zuckerberg said the company used to set time goals, but does not run the company that way now. He added, “When there’s something of value, people tend to use it more.”

Meta has said it bars users under 13 and has taken action to protect young users. In court, Mark Lanier, a lawyer for KGM, presented an email that raised concerns that the age limit was “unenforced.” Another 2018 presentation discussed retaining “tweens,” despite the stated age restriction. 

Arguing against Lanier’s statements, Zuckerberg expressed that he “always” regretted not making progress on identifying users under 13, but said the company reached the “right place over time.” He said Lanier took the tween document out of context and pointed to discussions about a version for children under 13 “in a regulated way.”

The trial also includes Google’s YouTube as a defendant. TikTok and Snapchat settled shortly before trial, with terms not disclosed.