A former engineering director at Meta Platforms testified on Wednesday that ​CEO Mark Zuckerberg fostered a culture that treated child safety as secondary to growth and engagement on Facebook and Instagram.

Arturo Bejar, a vocal critic of Meta's ‌safety record, made the allegation during his second day of testimony in a landmark trial over claims brought by a coalition of states that could reshape Facebook and Instagram, some of the most popular apps on the planet.

California, Colorado, Kentucky and New Jersey accuse Meta of designing the platforms to hook young users, fueling anxiety, depression and even suicide, and misleading consumers about their safety.

Those states and 25 others also accuse Meta of violating federal law ​by improperly collecting and using personal data of children under 13 while they used its platforms.

Experts have said the trial is the biggest legal test yet of social media's ​effects on young users.

It began in the Oakland, California, federal court on Tuesday and is expected to last six weeks. Jurors are expected to ⁠issue an advisory verdict, and U.S. District Judge Yvonne Gonzalez Rogers will decide whether Meta is liable and, if so, determine any civil penalties and changes to Facebook and Instagram.

MOVING MOUNTAINS

Bejar, ​the states' first witness, said Zuckerberg was closely involved in much decision-making, and the Menlo Park, California-based company's top-down culture ensured that product design changes would occur only if he ordered them.

"If Mark ​makes something a priority, mountains move in months," Bejar said.

He disputed Zuckerberg's October 2021 comments following allegations by whistleblower Frances Haugen that Meta knew its products were unsafe for children and knew how to make them safe, but did nothing in order to pursue higher profits.

Zuckerberg said at the time that Meta constantly used research to improve its products. In response, Bejar said he emailed Zuckerberg to flag his safety concerns.

"It's so false, every ​part of it," Bejar said. "You just cannot trust Mark Zuckerberg with kids."

MISOGYNISTIC COMMENTS TOWARD DAUGHTER

Bejar worked at Meta from 2009 to 2015, and examined the well-being of teenage Instagram users while ​employed as an independent contractor from 2019 to 2021.

He testified before a U.S. Senate committee in 2023 that Meta was aware of harassment and other harms facing teenagers on its platforms but failed to address them.

Under cross-examination ‌from Meta's ⁠lawyer Brian Stekloff, Bejar acknowledged he was unaware of the harm his teenage daughter would face when he helped her set up an Instagram account, which she still has.

Bejar said his daughter wanted a space where women could discuss cars but came to experience misogynistic comments, including about her breasts. She was 16 in 2021 by the time her father emailed Zuckerberg about safety.

"I kept an eye on how distressing it was for her," Bejar said. "She got a good following, at the price of harm."

During his testimony, Bejar also acknowledged that Meta employs hundreds of people focused on ​safety, including people he considered well-qualified. Bejar said ​he was not working directly with Zuckerberg ⁠during his second stint, and as an outside contractor lacked access to some resources.

PROFIT OVER SAFETY

Earlier, Bejar told a lawyer for the states that Meta prioritized user engagement and profit over safety.

He said a tool Meta uses that encourages users to take a break, a key feature of ​Meta's defense, was "designed to fail" because it is not the default setting and reminders are easy to ignore.

He called it "common knowledge" at Meta ​that most parents did not ⁠have time to understand the company's products or how their children used them. Meta, he said, had technology to flag potentially millions of users suspected to be under age 13, but adopted a "don't ask, don't tell" policy because it would boost profits longer-term.

After Bejar finished testifying, jurors heard recorded testimony from Elena Davis, a Meta researcher who looked at the alleged addictiveness of social media.

She read from her ⁠report that Meta ​could change Facebook to have "less potential to be habit-forming and provide support for people to 'break' Facebook habits they don't ​want."

Meta faces thousands of similar lawsuits over alleged harm to children. Bejar has been a key witness against the company at four trials. One of those cases, brought by New Mexico, resulted in $942 million in damages and penalties and an order ​requiring Meta to change its platforms in the state.