"The BOFH would more likely leave it in a drawer of the boss's desk.
So much extra satisfaction from getting the boss to cut his own throat."
This is assuming that the PHB knows what it is. So few can find the power switch on a computer. Leave it in a receptionist's or secretary's desk. Somebody that may have lots of down time during the day and may go through their desk and play with random things. Put some popular music or a video on so it stays plugged in for enough time.
Biting the hand that feeds IT
