My girlfriend has bought a jacket in Metro mall a while ago. Yesterday we went into music records store and the RFID detector beeped. During next 5 minutes we were standing near the detector to figure out what exactly causes this behavior. It turned out that one little sticker with barcode was forgotten to be removed by the shop assistants so that could probably cause some annoying looks and questions from the security of every other shop.
I recalled someone’s post that if you wrap the RFID tag with a foil it will fail to be powered by the scanners and thus will not be able to send the ID. So I took Orbit chewing gum pack, put the tag on it and passed all the scanners w/o any trouble.
It does not mean I want to steal anything but looks like every security feature has its flaws. You can read more about RFID at wikipedia: http://en.wikipedia.org/wiki/RFID.