The RFID hacks keep coming fast and furious -- hot the heels of that Mifare / Oyster Card exploit, the crew at BoingBoing TV has posted up a little demo of how easy cracking the RFID encryption on an American Express card can be. All it takes is an $8 dollar reader easily available on eBay, some software, and the courage to walk around with a laptop waving plastic boxes at people's butt pockets, but developer Pablos Holman says he's hoping to develop a newer version that will allow him to be a little more discreet. The root of the problem is apparently the fact that the system uses local decryption rather than sending card info to a secure data center, but either way we've been worried about this for a long time -- we're sticking to loose change and the barter system from now on. Video after the break.