I wouldn't get caught messing around with the systems. I made this mistake and nearly got expelled. On a positive note, it did land me a summer job configuring security on all the school district's computers. Unfortunately, it turns out that I was doing it all pro bono...

I miss DOS. Nothing like a bogus autoexec.bat that starts with ctty nul and a loop.... I used to have one that played Dixie over and over!