From Homestar Runner Wiki
A WikiTroll, unlike a WikiGnome, is a person who purposefully defaces a document on a wiki. There are a few methods in place for dealing with WikiTrolls.
 How to revert a page
Any page can be reverted to a previous version. Simply click "diff" in Recent changes, and then click "undo". State after the text that is already in the summary box that you are reverting because of a troll and click "Save page". This can also be accomplished by comparing versions of a article in its page history.
After repeated defacings, an offender's IP address can be blocked by several users who have sysop rights. These admins pay careful attention to the recent changes page, and will block IP addresses where/when appropriate.