Amazon did not alert its New York City customers that they were being monitored by facial recognition technology, a lawsuit filed Thursday alleges.

In a class-action suit, lawyers for Alfredo Perez said that the company failed to tell visitors to Amazon Go convenience stores that the technology was in use. Thanks to a 2021 law, New York is the only major American city to require businesses to post signs if they’re tracking customers’ biometric information, such as facial scans or fingerprints.

Amazon introduced its Go stores in 2018, promising that customers could walk in, take whatever products they wanted off the shelves and leave without checking out. The company monitors visitors’ actions and charges their accounts when they leave the store. It opened its first New York location the following year, and has 10 stores, all in Manhattan, accor