I've thought about that and I still don't have a good answer. My guess is that it is only marginally more theft-prone than the self checkout stations. It probably helps that the store is in an affluent suburb. They won't be setting up such a system in Baltimore where I live any time soon.

When I lived in the area I only used the system once because it just took too long. My mom stopped using it because she found on one trip she had effectively stolen two items by forgetting to scan them and was so horribly embarrassed she gave up on it.

Indeed. Google Wallet? As he described the scan-and-walk process, it sounds more like Google Shoplift -- but maybe that's just the first thing that came to my mind. Of course, if you had some kind of disposable "smart bag" to do an RFID scan of its contents, you might be getting somewhere with this.

I think that's overengineering. Why not just use weight, like they already do in the self-checkout line? Weigh the shopping cart full of groceries, subtract the weight of the cart itself, and compare to what they're paying for. If it seems wrong, investigate.