So old hat...
My Junior year in HS at Redlands Sr HS, Redlands CA

something JUST as good was pulled.
At the beginning of the year, during a motivational movie shown to the whole school assembly, cut in the middle was about 3-4 minutes of some rather interesting stuff involving females and synthetic male parts

.
It was shown behind the school principal who was trying to give a "let's start the year off right" motivational speech. Needless to say, when that hit the screen, he thought he had really gotten through to us

until he turned around..and almost fell over.
No way anyone was able to get to the projecter in time to stop it. This was in 1976, so the entertainment had to be spliced into the movie ahead of time. While I was not directly involved, I *do* know who was involved in such a dastardly deed.

*cough* They were never apprehended