With the iPhone 5S, Apple has introduced biometrics to the masses. Users can now unlock their phones using their fingerprint. While some see this as a good opportunity to get away from passwords, usually considered cumbersome, biometrics have obvious shortcomings.
It all boils down to the difference between identification and authentication: while a fingerprint is unique, it is hardly secret (it’s all over your smartphone!), can be duplicated without you noticing, and it’s really, really hard to change if compromised.
A group of German hackers already managed to crack the iPhone 5S biometric unlocking mechanism using a fake fingerprint, proving it is certainly not more secure than a simple password.
In fact, a fingerprint is more like a user name: it identifies you but is in no way sufficient to authenticate you. Passwords still are the recommended way to prevent anyone from accessing your private data.
The danger here is to blindly trust new technologies: they sound great and look like magic, thus people tend to embrace them without understanding the consequences first.
No technology, no matter how advanced or cool looking, can replace common sense.