Years ago I used to work a guvmant site. They had really strict security rules for internet and how you spent your time. Makes sense considering what that site did. I was a support engineer for some of their process control equipment.

I was approached by an operator supervisor to install dvd player software on a business machine (non process related). Basically just a general purpose PC with no function other than time cards and general office use. I was fine with the request, but the reason was for watching movies during a holiday period by the operators. Not for anything official. So I made some noise about my dislike of this request feigning moral superiority. But the supervisor swore up and down it was for "training" dvds.

So I wrote a simple windows script. The script basically popped up a window that said:
"Security has detected unauthorized media inserted into this machine. Please state the reason for this infraction." It provided a dialog to enter a justification. After you entered the justification it said: "Security has been contacted and your user logged. You will be contacted shortly."

This script was then attached to the supervisors Start folder so it ran when he, and only he logged in. We made sure the "training" video (some movie) was already inserted at this point.

He logged in. He just about shit his pants when reading this. He promptly logged and left the building to walk somewhere else in the site. We called him and let him know it was a gag. His response: That son of a bitch Demolishun!