THe cheaper cash machines leave all the tones open for anyone to record. I've listened to it myself thinking that its just a cheap modem in those things, and they 'leave' the friggen speaker on during the tranmissions! Most people wouldn't notice the tones, but anyone with half a brain could just record those tones and decode them later!!! They would have everything they would need to make a fake ATM card complete with your pin number, account information, and everything about you - probably enough information to steal your entire identity let alone your cash!
-S
__________________
 
|