Re: I wasn't scared before...
> I never did get the idea behind biometrics for two reasons: you can't hide it and can't change it.
It's actually pretty good as a replacement for your username (which should be considered near public anyway), i.e. identification, other than that you can't change it (so not quite so convenient for forums as the like).
The problem with that, though, is there will always be the eejits who think biometrics are a good replacement for authentication. So, if you use it for identification, and someone else uses it for authentication, you get an overlap between data that can be public (i.e. usernames) and data that should be secret (i.e. passwords). Not quite as trivial to steal and use as a simple username string, but it does open the possibility of it happening - historically there's not been much effort put into protecting handles because they're considered publicly available knowledge.
So using biometrics for authentication is stupid (can't be changed if/when it leaks, currently technology is good but far from perfect etc), and using it for identification is a potentially bad idea too.