How easy it is to steal...got 3 peppers? Just put in 2.
Maybe mis scan that steak...like pass over the scanner with a thumb on the bar code.
MOST folks are honest but a growing number think its no biggie.
All they need to do is to put RDF tags (or whatever their called) on every item .
This isn't rocket science, as you pass though the portal it scans everything in your cart. Tags are cheep now but could be even cheaper if mass produced.