DisRuption
Anybody can edit a wiki page. Doesn't that mean wikis will be disrupted by assorted spammers, idiots, nuts, etc.? Not necessarily. In the original wiki, http://c2.com/cgi/wiki, this hasn't really happened. It hasn't happened too much on WikiPedia.
How can this be? Simple. Anyone can edit a page, and all the recent edits are saved. So if some irresponsible individual ruins a valuable page, it can be quickly restored. Moreover, the irresponsible individuals know this. So they have little incentive to try to wreak havoc.
We might end up with people posting silly quotes, but that's to be expected...
"Share your knowledge. It is a way to achieve immortality." -The Dalai Lama