Just a quick link in case people don’t follow Wired News these days. They have an article about Wikipedia Scanner (down, at the moment, due to the overload), a mash-up of wikipedia data and a reverse DNS lookup to show where anonymous posters are posting from. Looking up suspicious IPs isn’t hard to do, but indexing those anonymous edits is very interesting, since you can track down all the anonymous edits that are from a particular IP range (e.g., the Republican Party headquarters or the CIA).
Of course, those people making anonymous edits with their IPs showing were either (a) not trying especially hard to hide their manipulations or (b) didn’t know any better. I am guessing that in most cases it is the former. Keeping your identity quiet on Wikipedia is fairly easy. First, anyone can have an account, and accounts (I believe) don’t show the IP. But that’s a superficial layer of protection. You can always make edits from an internet cafe, or through Tor, or both!
Wikipedia Scanner needs to either backstop their servers to handle the flash crowds, or provide the database as a torrent. I suspect they can’t do the latter because they didn’t use open source GeoIP data (doh!).