Wikipedia has not always been scrupulous about maintaining its entries. There have been several high-profile cases where libelous statements about folks have been made and wikipedia has been unresponsive in resolving the issue.
That's exactly why I almost never bother looking at wikipedia. There's a general relationship on the internet (or in general), that past a point the more people that have input to something, the less value it has. That's pretty much just straight up censorship though.