I was reading through the Android Compatibility Definition document after a friend pointed me there while we were discussing fingerprint scanners and other biometric authentications. I noticed this requirement that seems unusual:
MUST NOT enable 3rd-party applications to distinguish between individual fingerprints.
I found this article which seems to be wondering the same thing, with no conclusions, although one person in the comments suggests that it might be a way to avoid patent infringement. Now, I can definitely see patent issues as being possible - one useful patentable idea that comes to mind is a phone having two modes, the 'real' mode that you use, and a 'fake' mode that hides personal information, contacts, etc, which you unlock with a different finger, unknown to a person trying to force you to give them access.
I haven't been able to find any definitive answers, though, so I'm curious if there's something I'm overlooking. Are there any known security vulnerabilities relating to a program being able to distinguish which finger is used to authenticate?