[_asummers]

Fingerprints should not be treated as a substitute for a password. A password is "what you know", and a fingerprint is "what you have". If you also throw in "who you are" (retina sensors, blood biometrics, etc.), you have to combine at least two to have a proper system. By allowing the fingerprint scanners to become ubiquitous, they (Apple and Samsung) are training their users poorly.

Now one could make the argument that the fingerprint is more secure than a poor password, for most use cases. I'd tend to agree with that, with the caveat that it is no longer your decision (read: subject to your interrogation resistance) to open your phone if you are captured.