Now what happens when something is not sold but stolen? Guess what? Thieves don't check out and have their stolen goods scanned so no one knows they're gone except the thief. The shortfall is not discovered until a physical inventory is conducted, actually going out and counting the goods on the shelves.
Now with this new technology, the store would be able to automatically find out how many widgets were on the shelf, but more importantly, they could find a large quanity of widgets that were in somebody's car or in somebody's home.
Great for loss prevention. Bad for privacy.
Not without probable cause and a warrant. Of course the police will consider the "tracking data" as probable cause. But, what happens when the technology (or the LEO's) make a mistake and "bust" an honest citizen and Wal-Mart customer. Good PR, Huh? Do you realy think loss control has priority over customer relations? I don't.
No thanks. Wal-Mart can keep its "widgets" and I'll (try) to keep my privacy. You don't need my personal information to do inventory.