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.
The rabbit hole you fall into when you look up one thing, and end up falling deeper and deeper into online information (originates from, but is not limited to, Wikipedia) .
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.