Amazon is reinstating a pre-pandemic policy bringing back metal detector screenings for its 750,000 U.S.-based hourly warehouse employees, per a new Bloomberg report. The retail giant will also require workers to register their phones so security personnel know they haven’t stolen the devices.

Amazon reportedly began telling workers in select test locations about the phone registration and metal detector screenings on Monday. The company is planning to gradually roll out the anti-theft measures, starting first with test warehouses and then expanding to all of its U.S. facilities, per Bloomberg.

Under the new policy, employees will have to walk through a metal detector to leave Amazon warehouses to ensure that they haven’t taken anything with them. Phone registration entails sharing the last six digits of the phone’s serial number in exchange for an identifying sticker.

“We’re always working to make our facilities more safe and secure for our employees and for all companies of all sizes that put their trust in us to store their inventory,” an Amazon spokesperson told Bloomberg in an emailed statement.

Metal detector screenings aren’t new at Amazon warehouses — they were the norm before the pandemic. But they were controversial, and workers filed lawsuits over the screenings in 2014, seeking more than $100 million in back wages for time spent in line waiting to be screened. They alleged that they stood in line for up to 25 minutes at a time to comply.

^{Inside an Amazon fulfillment center in Robbinsville, New Jersey. Photographer: Bing Guan/Bloomberg via Getty Images}

That same year, the U.S. Supreme Court had the final say on the matter and ruled that workers weren’t entitled to back pay for time lost after a shift to metal detector screenings.

Amazon also stopped employees from accessing their phones before the pandemic, mandating that they leave personal devices in cars or lockers. The retail giant relaxed this policy during the pandemic as workers sought to be connected to real-time medical information, per Bloomberg.

According to Business Insider, Amazon operates 110 warehouses in the U.S. with some as large as a million square feet.

Statista estimates that Amazon is the second-largest company in the world after Walmart, with 1.5 million global employees as of 2023.