To anyone in or out of the US, we have a show called mythbusters on the discovery/learning channel. They did a test on credit cards and found that it takes quite a bit to clear/damage the data on the mag strip (the new credit cards especially (ya know, anything past 1990)). Hope it helps!
There are no stupid questions, only a whole lot of inquisitive idiots.
Stupidity should be painful.
Wallaby WM2003SE -- RIP
SX66 -WM2003SE Tmo UK, Camera Upgrade (yay) - sold
HTC Uni, WM5 (Thx Swat4) - sold
HD2 - stolen by thieving bass tards
G1 - upgraded to Cyanogenmod 6.1 = awesome