I have been doing a lot of research on the dangers of RFID bands and the security that it provides, it is very hard to find a lot of info on them because the government doesn't want you to know the risks and also what all they can do with these chips. Depending on the chip some have higher frequencies and can be visible from long distances away. Meaning the government or that company that gave you the chips, whether it be a wristband or surgically implanted or a company putting in hidden in their products they sell you; they can actually track you if they want. Consequently a  hacker might also be able to get ahold of this information, just think that if these RFID chips are as strong as they say they are then someone could possible walk into a room and scan everyones chips in the room and get all their info. Many major credit card companies have applied these chips to their cards therefore you will not need to swipe anymore you can simply swipe it pass a RFID reader.