Passwords and hardware devices also have an important safety feature that biometrics lack.

When you are cornered by a large dude with a machete asking about your password, you can hand them over and save yourself.

When he tells you to hand over your finger - or even worse, eye - you don't have a lot of options.

This is usually the place where some nerd with no sense of reality bursts in to say that good fingerprint readers can detect a pulse and will refuse to scan a cut off finger. The question then is, is he really going to believe that after cutting off one of your fingers, or is he going to think that you told him the wrong finger and start cutting off fingers until he has one that works, or you run out of fingers?

@leeloo
It depends how much you value the integrity of your computer and/or the confidentiality of your data Vs your fingers and/or eyes.

I imagine there are high-stakes situations where it's not as clear cut as you are making out.

@light
Sure, for example the guy guarding the vault under the Pentagon, you don't want him to hand over the combination to some guy with a machete.

But then he gets a gun that makes a machete a moot point.