Hi all,
After a few weeks on test.wikipedia.org, the Abuse Filter is rolling out for wider testing. For the moment, it's active on MediaWiki.org, but we're interested in deploying it to other small projects interested in targetting pattern vandalism.
The Abuse Filter extension allows very specific rules to be defined about the sorts of edits that may be made. It can take actions in response to edits ranging from simple tagging of an edit with a special mark indicating it needs extra attention, all the way up to emergency desysopping. Projects can ask for any subset, or all of these actions to be enabled on their wiki, and for advanced permissions to be required to use the higher-level ones.
The extension includes considerable useful tools for testing and debugging filters, and for evaluating their performance. A study last year indicated that a particular filter, if applied in August 2007, would have blocked 60% of all page-move vandalism on English Wikipedia over the subsequent year, with just five false positives (0.6%).
Primarily we're looking at the performance impact of the extension, so English Wikipedia (which the extension was written for) can't quite have it yet (as we're not sure that it will perform adequately under such high load). If other medium or small projects such as Meta, Commons, Wiktionary, Wikibooks, Wikisource and similar are interested in deploying this extension, they're free to develop a rough consensus and request deployment on Bugzilla.
If, after a few weeks, we find that the extension seems to work fine, we can hopefully deploy it on English Wikipedia (hooray!).
Thanks!
-- Andrew Garrett