Meta is pausing a divisive employee tracking program after an internal security issue exposed potentially sensitive data collected through the initiative to other workers.

“We have carefully designed this program with privacy safeguards and while we have no indication at this time that any data was improperly accessed by Meta employees, we’re pausing it while we investigate,” says company spokesperson Tracy Clayton.

Meta rolled out the Model Compatibility Initiative (MCI) tool in April to US employees. The tool “collects computer inputs such as mouse movements, click locations and keystrokes, as well as screen content,” according to workers who have been petitioning against it over privacy, security, and personal liberty concerns. When MCI launched, employees couldn’t opt out, but that changed to a limited degree after workers protested.

Meta executives have repeatedly defended the data-gathering project, saying it was necessary to train AI systems to operate computer software the way humans do and that employees were the best examples for the artificial intelligence to learn from.

On Monday, a Meta engineer issued an internal security notice stating that databases filled with information gathered by MCI had been exposed to anyone inside the company.

A former employee actively involved in pushing back against MCI describes the lapse as “a mess”—and one that employees had expected would occur. “When workers raised concerns, leadership doubled down and failed to acknowledge the risks workers raised about the safety and privacy of worker and customer data,” the person says. “Leadership has clearly created an authoritarian environment where workers are no longer respected or heard.”

But after critical comments poured into internal forums on Monday expressing frustration about the security issue, Meta shocked some of its staff by pausing MCI altogether. It informed WIRED about the development before announcing it to employees, according to two people familiar with the matter.