Slashdot reports of an arrest that uncovered what may be an increasingly common practice, at least in some parts of the world. Surgery was used to transpose finger tip skin grafts from one hand to the other. The result allowed the woman in this case to get past security measures at the Japanese border.
I can imagine fingerprinting procedures getting an update to deal with this trick. More clever versions could potentially bog down fingerprint identification considerably. Transposing any finger to any other yields a rather heft permutation space to search through.
It also occurs to me that for those with strong stomachs and/or a pressing need, this could be a way to legitimately revoke biometric credentials. I am not suggesting the possibility legitimizes biometrics as a sole means identification and authentication. Regardless, I will have to qualify my refrain when discussing finger print readers, that there is no way to revoke credentials. Rather there is no sane or reasonable way to undertake such revocation, even if it is proven to be technically possible. Compare surgery to just invalidating an RF card if you want a bead on what I mean by reasonable.