Hi, thanks so much for the bug report.
I've been thinking about this quite a bit lately. I'm going to have to mark this "won't fix" for now.
The prevailing opinion from security professionals is that fingerprints are perhaps a good replacement for usernames. However, they're really not a good replacement for passwords.
Consider your laptop... How many fingerprints of yours are there on your laptop right now? As such, it's about as secret as your username. You don't leave your password on your spacebar, or on your beer bottle :-)
This wikipedia entry (although it's about Microsoft Fingerprint Readers) is pretty accurate:
So, I'm sorry, but I don't think we'll be fixing this for now.