How secure is it?

Was currious how secure knoppix is and how traceable. If I use it at work, unless someone is standing directly over my shoulder, will they know I am using it? I do not plan on being destructive, but we cannot do alot of things here that knoppix would allow me to do, i.e. chatting and downloading files to my portable for my LFS system I am building. I can do most at home but the connection is so much faster here for down loading the larger files. Any feedback is very much appreciated :)

everything you do on a network ic tracable to both IP and MACadresses, that and time+where the computer was connected.
so no matter what, it is possible to trace.
and ofcource the programes used in any OS leave their special telltales aswell.