It’s been said before, but a person’s first foray into free culture of any type is often to scratch an itch. For me, my first Wikipedia edit was undoing vandalism on the Hernando de Soto Polar page conflating him with the conquistador of the same name—replacing his actual birth date with 1500-something, etc.
It’s somewhat disappointing that real Wikipedia vandalism is as pointlessly childish as that…
James Cape 
The day that participation in software development becomes as easy as participation in encyclopedia development (I never thought I’d be saying that) will be the dawn of a new age of computing. Seriously, a Web-based IDE would absolutely slay.
As for creative vandalism, the problem is that it tends to get undone. The types who really enjoy elaborate hoaxes usually just write entirely fictitious biographies on Uncyclopedia these days I think.
– Chris