Darsey Litzenberger
(formerly: Dwayne Litzenberger)
lfingerd is a simple Finger User Information Protocol server (written in Python) that allows each individual user to have full control over what is returned. It is distributed under a BSD-ish licence. I believe it is secure, but I'm not making any promises.
You may download lfingerd from: http://ftp.dlitz.net/pub/dlitz/lfingerd/.