RFID tags in currency notes
One of the disadvantages of using credit card is that each and every transaction of yours can be tracked by authorities. So some of my friends used to spend in cash so that they need not disclose their source of income (you know whom I am talking about 
, but with these new bills which have an RFID tag embedded into them they can track you even if you make purchase using cash. And also the way someone microwave a PDA if you microwave this RFID tag embedded bill it explodes. Do read the article I found it bit interesting.
