I work at the front office for a Marriott in the north east. Just recently people have been afraid of identity theft due to the information kept in the magnetic strip on your hotel key cards. I just want to say this is total BS. The strip is extremely sensitive to cell phones, laptops, speakers and most credit cards and can barely hold any useful info…they are easily erased of information. All that is recorded is your last name, some random number (either 5 or 9 digits long) and your length of stay. It’s really nothing much. If you have questions on hotel policies or your rights to privacy, please ask. There is so much. Have any of you had an identity stolen and it was proven and tracked by your hotel key card?
-M
This must be a relatively recent urban legend. My own fiancee mentioned it as we checked into a Memphis hotel last weekend.
According to Snopes:
ANYTHING can be recorded on the magnitic strip, but not much is. In the hotel where I work, only the room number and length of stay and security code. The lock only remembert the date and secutity no. and if a different no. is recorded the old one is erased so old cards,even for that room, will not work.
Spelling and grammer subject to change with out notice.
There was a memo sent out via global e-mail at my company early last year warning about this so-called threat. Employees were ordered to keep their key cards, bring them back to the office and run them through the shredder. I was appalled. But this issue has been floating out there for a while and its become pervasive and the privacy uber alles gang are right on top of it thanks to the ever-increasing fear of magnetic strips. 
I used to be the system admin at a large hotel. I found this to be laughable. First of all, why would anyone want to record cc info on a key card, when all desk clerks, as a matter of fact, most employees can walk right up to the FD computer and get the info off the bill.
The biggest complaint I have had at every hotel I worked at is Desk Clerks and the Accounting dept do not shred cc receipts. The controller at my last hotel refused to saying she was too busy. Though this is corporate policy.
Anyone with an ounce of brains knows the garbage is the best place for CC numbers.
BTW it is VERY easy to put CC on a key card. But why would you.
I worked at a SLEEP INN part time, when I lived in Florida. We had a great KEY SYSTEM. If you paid by CC we would use your CC as the key card. It was really cool. (BTW we also had key cards for cash payers and people who didn’t want to carry their CC)