This article says that Amazon is using cameras and AI to implement this. IBM and others are working on RfID technology that would make "grab and go" grocery stores much easier to implement. Here is an advertisement showing how this would work:
https://www.youtube.com/watch?v=eob532iEpqk As you see, the scanner works at a distance and it scans all items simultaneously. A few years ago, RfID tags were still too expensive for grocery items, but the prices were falling rapidly. I think this system is inevitable. - Jed
