Arturo Bejar, a former director of engineering at Meta Platforms, testified on Wednesday that chief executive Mark Zuckerberg was responsible for failing to protect children who use Facebook and Instagram, shirking responsibility for their safety.
Bejar, who worked at Meta between 2009 and 2021 and has since become one of the company's most vocal critics, told a federal court in Oakland, California, that Zuckerberg was deeply involved in many major decisions and that the company's hierarchy ensured product design changes happened only if he ordered them.
Bejar said that when Zuckerberg makes something a priority, mountains move within months.
Bejar is the first witness in a landmark trial over allegations brought by American states that accuse Meta of designing its platforms to addict young users and of illegally collecting data from children under 13.
He also challenged an October 2021 response Zuckerberg gave to allegations from whistleblower Frances Haugen, who said Meta knew its products were unsafe for children and knew how to make them safer but did nothing, chasing greater profits instead. At the time, Zuckerberg said the company constantly used research to improve its products.
Bejar said that response was entirely false, in every part, and that Zuckerberg simply could not be trusted with children.
States accuse Meta of targeting young users
California, Colorado, Kentucky and New Jersey accuse Meta of designing Facebook and Instagram to addict young users, fueling anxiety, depression and even suicide, and of misleading consumers about the platforms' safety.
Those states and 25 others also accuse the company of violating federal law by collecting and misusing children's personal data while they used its platforms.
Meta has denied the allegations and argued that Bejar's opinions fell outside the scope of his job. He began testifying in the Oakland federal court on Tuesday, when the trial opened. The proceedings are expected to last six weeks, and Zuckerberg is expected to testify.
Safety was an afterthought, witness says
Bejar helped lead research into teenagers' experiences as part of a team that examined well-being on Instagram between 2019 and 2021.
He has been outspoken in criticizing Meta's safety record for children, and testified before a US Senate committee in 2023, telling lawmakers that Meta was aware of harassment and other harms faced by teenagers on its platforms but failed to address them.
In Wednesday's testimony, Bejar said Meta used metrics such as meaningful social interactions and daily active users to reward employees, prioritizing user engagement and profit over safety.
He also said a tool Meta uses to encourage users to take a break, a feature the company has cited as central to its defense, was designed to fail, because it is not turned on by default and its reminders are easy to ignore.
Bejar said that paths from every side lead back to time spent on the product, and that in that context, safety was always treated as an afterthought.
Detecting underage users
Bejar said Meta had technology capable of flagging and requiring verification from users suspected of being under 13, potentially numbering in the millions, but turned a blind eye to the problem through a "don't ask, don't tell" approach, because it was financially profitable in the long run.
He said that wherever the youngest users are is where users will be in the future.
Wider legal fight over youth safety
Experts say the trial is the biggest legal test yet of social media's effects on young users.
Meta faces thousands of similar lawsuits over alleged harm to children. Bejar has been a key witness against the company in three of the cases that have already gone to trial. One of those, brought by New Mexico, resulted in $942 million in damages and penalties, along with an order requiring Meta to change its platforms in that state.
