Yeah I've heard of that happening and it sucks, I've made a few anonymous edits in the past and they seemed to have been accepted OK so I guess it's a hit-or-miss situation depending on the personality of whomever is "guarding" the page or if anyone cares that much or not.
At least when it comes to "self-policing" online communities what usually happens is that they attract pathological types whose primary desire is to be a big-shot who backs up and is backed up by other big shots and eventually they run the actual expects (who tend to be more equitable) out on a rail with their drama-producing behavior - actual experts have better things to do with their time.
That said Wikipedia I think it's remarkable how valuable a resource Wikipedia can be given that its "model" was very optimistic and doesn't really make much sense now.