At pretty much any store, if you tried to just walk out with stuff, you’d be arrested for shoplifting. But Amazon is about to turn that idea on its head. The world’s biggest online retailer is testing out an old-fashioned brick-and-mortar grocery store—but with a futuristic twist: Amazon Go, which opened in December at the company’s Seattle headquarters, has no lines or cashiers; customers just scan their Amazon app at the store’s entrance, take what they need, and leave. The store uses artificial intelligence, sensors, and other technology to track customers’ shopping carts and know exactly what they have in their bags when they exit. The app electronically bills customers after the shopping is complete. For now, the 1,800-square-foot store is just for Amazon employees, but it’s expected to open to the public this year, and other locations may follow. Though some see Amazon’s cashier-free model as a threat to jobs, others think it’s the wave of the future. “It’s going to create enormous advantages for consumers,” tech expert Martin Ford told CNBC, “so it’s an inevitable process.”