How common is vandalism on Wikipedia?
It is pretty common for people -–often schoolkids just playing around– to try to vandalize Wikipedia. This normally takes the form of trying to erase entire articles, edit Wikipedia to make fun of other kids, or insert joke material into articles. (There is some good discussion of attempted vandalism in this lovely article about Wikipedia by novelist Nicholson Baker.) However, Wikipedia has a variety of filters and bots designed to prevent vandalism before it’s completed, or revert it immediately after it’s done. So, most vandalism is never seen by anybody. In general, Wikipedia is inherently resistant to vandalism. All previous revisions of an article are saved and stored, which means that when vandalism is committed, anyone can instantly revert it. This ease-of-reversion is the cornerstone of Wikipedia’s response to vandalism, and is supported by a large number of volunteer “vandalism patrollers.” Having said that, we can’t guarantee that people won’t stumble across vandalized pages
