Good thing the Founders wrote Copyright into the Constitution, so it is on an equal footing with Free Speech, then. This is not an accident. Copyright is an intentional restriction of the public's rights to communicate and express themselves.
... ultimately, no system can guarantee that the actual finger or eye or DNA was scanned - all that the 'server' can verify is that the correct 'data' corresponding to previously recorded data, was transmitted over the network to the server. So, compromise a terminal (or setup a computer which masquerades as a valid 'terminal'), then send the correct 'data' from that terminal, and the server will assume that the user's thumb or retina was scanned.
A properly-designed system would have the data sent by the terminal encrypted, so to compromise the system the hacker needs not only the geometric information on your finger or retina, but also the terminal manufacturer's private encryption key.
It's not clear that the biometric ID is better than using a library card with a barcode, but perhaps the biometric system is cheaper since you don't have to print and issue library cards and deal with lost cards, etc.
Not only will The Hobbit's copyright not expire in 2012, but in fact with rare exceptions no copyrights will expire in that year, or in any other year until 2019. The change in copyright terms was motivated by the then-imminent expiry of the copyright on Mickey Mouse.
Unix is the worst operating system; except for all others. -- Berry Kercheval