Ah, that explains a lot
Well, considering the latest fingerprint readers (which are just a couple of mm thick) I don't really think that's possible anymore. Still, one could copy a fingerprint but could as well do that from the cup you're drinking off or the mirror/glass door you last put your hands on. Chances are (again) very low for someone to do that.
As far as I'm concerned, you not only need fingerprint to get in to your bankaccount. You also need codes and if walking into a bank with a 'third arm' isn't suspicious enough, even then it's hard to just copy a good fingerprint.
It's not like taking a bit of powder and taking some tape to put the print on it.
So I guess you're quite safe there. There'll always be a risk (everywhere, whatever you do, not only fingerprints). But you shouldn't worry to much about it. If you're worried about the fingerprint, try also looking for more possible security options like an extra code you'd need to gain access to personal data for example. And an authenticator like banks often use (or games like WoW).
I hope I helped you with this one a bit more!