A grocery chain in Chicago (Jewel/Osco) tried that about 20 years ago. My local store was a test site. You got a wireless Cisco barcode reader that undocked whe

A grocery chain in Chicago (Jewel/Osco) tried that about 20 years ago. My local store was a test site. You got a wireless Cisco barcode reader that undocked when you entered the store and scanned your shopper card. Then you scanned the card again at the self-checkout and the entire order rang up. A random % of people were spot-checked as they were leaving. The project was abandoned about a year later. Manager said the shrinkage (theft) rate got way too high. And this was in a pretty affluent town.