I hacked a fingerprint scanner using some play-doh and RTV gasket maker. Used the play-doh to make an impression of my finger which served as the mold for the RTV. Left it overnight and tried it the next day. Took a couple tries, cleaning the ridge detail and eventually licking it to make the plastic fingertip work. Did this right after watching the Mythbusters show about it. The difference was that they stole a fingerprint for theirs whereas I used my own and used a technique that would not "steal" someone's fingerprint. What it COULD be used for, though, is establishing an alibi. Work at a company that uses fingerprint scanners that you can use after hours? Have a trusted buddy use your badge/fake finger to move around the building while you are on the other side of town doing some crime. If they trace the crime back to you then ask your company to produce fingerprint scanner access logs that "prove" you were elsewhere.... Then hope they don't have equally "good" evidence of the crime... u mad, cops?