Reply #4: Actually not far off...

[Solon]

He's talking about the "Shoplifter's bag", usually the best example is a potato chip bag. Use one to line a pocket and you can walk out with as many CD's as you want, because it blocks the scanner at the front of the store. Not that I know anything about this, of course. I imagine it would work in the reverse too, by blocking the RFID signal, it is weak, and you can walk out of the store, because according to the reciever, you never had the item in question in the first place.