This ComputerWorld piece doesn't fill me with warm fuzzies - Wells Fargo (and other banks) have deployed web-enabled ATM's:

Wells Fargo & Co. last week said it has completed a five-year project to Web-enable its 6,200 ATMs in 23 states. The Windows-based infrastructure is designed to allow Wells Fargo to update its entire network remotely when it needs to do things like add new languages and enable customers to make envelope-free deposits.

Sure, Windows can be secured (although in practice it rarely is). The web enablement is what worries me. I'm sure that the banks will figure out how to secure them - it's just a matter of how bad the damage gets to be while they go through their learning curve.