Fingerprints and other biometric authentication tokens
Why fingerprints make lousy authentication tokens - Boing Boing: "This is the paradox of biometric authentication. The biometric characteristics of your retinas, fingerprints, hand geometry, gait, and DNA are actually pretty easy to come by without your knowledge or consent. Unless you never venture into public without a clean-room bunny-suit, mirrorshades, and sharp gravel in your shoes, you're not going to be able to stop dedicate strangers from capturing these measurements. And as with Schauble's fingerprints, you can't revoke your DNA and replace it with new DNA once a ripoff artist has used it to clean out your bank-account or break into your workplace."