One issue is that, with lots of contributors and the place being too big for everyone to know everything that goes on, new people regularly rediscover blown-up controversy written in certain notorious off-Wiki places and cause a fuss about it - in many cases because they don't realize the unreliability and maliciousness of those accounts, and in some cases because they do and like the drama, or like the fact that the external site criticises someone they don't like.
We do need to shut down such things quickly; constant rehashing of stale issues and false accusations is damaging, harmful and pointless. However, the best way of doing that seems to me to be (a) to document somewhere that site <whatever> is a known malicious and unreliable source and things there should not be trusted, and (b) to close such discussions down politely and inform people why we don't want such issues brought up again.
Wikipedia needs the minimal-drama way of doing this. We have a job to do, and that job isn't squabbling endlessly or obsessing constantly about the minutia of our affairs and what others are saying about us. Such sites as Wikipedia Review, Encyclopedia Dramatica and Antisocialmedia are best *ignored* as irrelevant to our real job of writing an encyclopedia.
-Matt