That's a good question. The first time I saw an edit (on the article for Brooms, someone changed Broom to Penis), I thought it wasn't changed just because it probably wasn't a very popular article. Not enough people viewing to catch it. But then I saw Hillary Clinton's picture turned into a picture of a penis and it stayed up for a few hours, and that's gotta be a pretty popular page.
Damn, wikipedia jokesters are obsessed with penises.