It's not that difficult to create a bot / script that undoes edits made from a list of IP's / IP ranges.
What's needed, basically, is to:
Every couple of minutes: { Fetch RecentChanges from the server For each IP on list: { filter for IP address For each mentioned page not removed: { Send http request for EditCopy Send http request to click Save button From different IP address: { Send http request for Edit Add or delete one whitespace character (null changes are rejected) Send http request to click Save button } } } }The above is easily done in PerlLanguage, JavaScript or similar. A bit harder, but certainly doable, in C++ or similar.
More complex versions could possibly:
But what even the simplest version of such a bot would do, effectively, would be denying edits by a particular user or group of users, since most of us have either a fixed IP or an IP within a certain range.
MichaelSparks seems to have used a similar approach in fighting spam (since a lot of spam seems to come from a limited range of IP's).
See also: WikiBot, WikiVandals, DefensiveScriptIdea