Security experts familiar with the cards' radio frequency identification (RFID) technology, described by Chase as "contactless functionality," expressed some concern over the devices' security strength. Some have suggested that they may make it easy for perpetrators to commit fraud or identity theft.

Saw an add for ChaseBlink tonight. This ought to be interesting... Contactless credit card purchases. No signature. No pin. Just waive it over the reader. I can tell you how I'd have designed it, but I would be suprised if there were no vulnerabilities here.

While this is rather elaborate, a computer controlled rfid device connected to increasingly common cellular wireless internet systems relays the transaction to another reader, maybe taped to a chair in a shopping mall foodcourt.

CRM News: RFID : Chase Bank Rolls Out Contactless Credit Cards