Editors of WikiPedia articles (mostly admins) that suck the fun out of participating, by nit-pickingly enforcing every rule, thus driving out those who have knowledge of the subject matter, leaving only fellow WikiNazis.
What You See Is Not Always What You Get. An acronym especially appropriate to the Internet when you're trying to print something from a webpage and it doesn't come out the way you want it to.
Person on Wikipedia who gets off on killing well-written articles of others. Subscribes to a ridiculously strict, yet abstract standard for what is and isn't "encyclopedic." Probably molests children in spare time.
There are many examples of Wikinazis: Lee Hunter, RickK, Ambi, just to name a few.