I'm surprised that an ATM would even store a credit card number for longer than it takes to complete a transaction. Yes, there would be paper audit copies of the transaction slips, but those are picked up when they put money in, aren't they?
Anyways, even without sensitive data, an ATM could be set up to pretend it was still online, and get people's PIN numbers, so besides removing the hard drives, they need to remove the trademarks of whoever owned it.