Ooh I can kinda answer for once.

I was in a Computer Science class my Senior year of high school. It was an intro course, but since it was new two of my extremely overqualified friends were taking the course for an easy A. About halfway through the first week, our teacher gets annoyed that we're playing games during class (we had finished our assignments for the day, and were playing Halo on LAN).

Next week we come in and he's installed this software onto all the computers (called something like VISION i think). This software gave his computer the power to remotely control our computers and lock us out of it. By the end of that class session my friends wrote a code that blocked that program from locking us out, but still made it look like VISION was "working".

I forgot to have their program running a few times, and when I did, halfway through a game my client would pause, and my mouse cursor would slowly move it's way towards the application window and close out.

Nobody got in trouble for it, and we all got A's in the class (even me, and I'm shit at programming)