The funny thing about an abuse of power is that sometimes you might not even realise you have power until you've abused it. Trust is power, and playing pranks on people can sometimes cross that line where you are abusing that trust and therefore abusing your power.
I'm thinking of a moment on Mythbusters. Very early on, they were testing whether a Leydon jar could put out a noticeable electric shock. The then-known-as "build team" hooked up an electric fence generator to their mock-up Ark of the Covenant, but told Adam Savage it was just the Leydon jar, which would have been a much milder shock. He actually asked them "you didn't hook up the fence generator to this, did you?" and they said no. The look of surprise and betrayal on his face when he got shocked said everything.
I've seen Adam talk about it at some conference, where he said the whole thing was the producer's idea, and that's probably the guy with the most power on set at any given time. That prank, I think, crossed a line into abuse of that power. Adam also said that he and Jamie Hyneman don't prank each other on the show, just because it escalates too quickly and gets way out of hand.
Mokalus of Borg
PS - I think that's sensible.
PPS - Though it doesn't sound like much fun, on the surface of it.