Automated fast food restaurant CaliExpress by Flippy, in Pasadena, Calif., opened in January to considerable hype due to its robot burger makers, but the restaurant launched with another, less heralded innovation: the ability to pay for your meal with your face. CaliExpress uses a payment system from facial ID tech company PopID. It's not the only fast-food chain to employ the technology. Biometric payment options are becoming more common. Amazon introduced pay-by-palm technology in 2020, and while its cashier-less store experiment has faltered, it installed the tech in 500 of its Whole Foods stores last year. Mastercard, which is working with PopID, launched a pilot for face-based payments in Brazil back in 2022, and it was deemed a success " 76% of pilot participants said they would recommend the technology to a friend. As stores implement biometric technology for a variety of purposes, from payments to broader anti-theft systems, consumer blowback, and lawsuits, are rising. In March, an Illinois woman sued retailer Target for allegedly illegally collecting and storing her and other customers' biometric data via facial recognition technology without their consent. Amazon and T-Mobile are also facing legal actions related to biometric technology. In other countries ... biometric payment systems are comparatively mature. Visitors to McDonald's in China ... use facial recognition technology to pay for their orders.