There's something about this notion that any given retailer is powerless to secure their own merchandise on company property that just doesn't sit well with me.
In the case of large items, such as wide screen TV's, A thief and a purchasing customer are virtually indistinguishable with regard to probable cause if, for arguments sake, we eliminate any electronic security measures from the item itself. In other words, the only difference between a thief and a purchasing customer is that the later passes through the register on the way out. This is because you can not conceal the item, therefore, behavior can not be an indicator as to intent. That seems to skew the odds in the thief's favor if he is able to defeat the electronic security measures. In such a case the store is only left with one option...visual confirmation of the receipt. I'm having a hard time believing that retailers are legally prevented from implementing such a system, in some way, on their own premises if they so choose. Of course, doing so may bad for business, which is probably why most retailers don't.
So, If Walmart knows that people are literally walking out the doors with wide screen TV's without paying for them, I'm to believe there's not a damn thing they can do about it?
Something doesn't sound right here...
There are many other tools besides receipt checking. Security tags that sound alarms at exits, paid stickers, video cameras, security and other staff observing shoppers, making expensive or easy to steal items inaccesible without staff assistance, putting all cash registers near exit, customer pickup areas for valuable items, etc.
If store staff observes an individual picking up an item and attempting to leave without paying they would have probable cause to detain the suspect or, I suppose, ask to see a receipt.
Most stores do not check receipts and shoplifting is not putting them out of business.