Ordering an unrequested pizza to someone's house or apartment, to their complete surprise. Generally followed by them coming online and cussing out whoever did it (if they know).

Internet persona(s) who happens to follow you and you happen to follow them back and maintain communication with and have a mutual liking for eachother whether it be friendship wise, etc. (Mutuals if more than one mutual)

Recieving unwanted pizzas called to your house by pranksters. See also taxied. In theory it is possible to be 'petting zooed' and 'clowned' by the same means.

When someone leaves their computer unlocked and you change their desktop background to an image of pizza, preferably a small image that is tiled several hundred times.