From Dustin Kirkland, an interesting way to think about fingerprints:
I could see some value, perhaps, in a tablet that I share with my wife, where each of us have our own accounts, with independent configurations, apps, and settings. We could each conveniently identify ourselves by our fingerprint. But biometrics cannot, and absolutely must not, be used to authenticate an identity. For authentication, you need a password or passphrase. Something that can be independently chosen, changed, and rotated. I will continue to advocate this within the Ubuntu development community, as I have since 2009.
From the Canyon Edge: Fingerprints are Usernames, not Passwords.