Stealing Legos for fun and profit?
Mad_Rain writes "Every nerd I know had (or still has) a fairly extensive Lego collection. But I don't think most would go so far as to steal $200,000 worth of Legos. When police arrived to carry away the evidence from his home, they needed a 20-foot-long truck. They found in the car of the accused a laptop computer that had a list of Target stores that he was planning to defraud along with the mapping software on how to get there."
You could use some sort of jamming device to block all RFID tags in a small area, but if the store can't read the RFID tag they'll have to do the equivalent of "Price check on aisle 5!", which will reveal the actual price of the item, thus nullifying all of your efforts.