Perhaps you could explain. So far, and I'm just learning, once you have the ip address you can then see where it is coming from and sometimes whether it is a fixed or dynamic address. Blocking of dynamic addresses is not good. You can also get an address to complain to, assuming the problem is serious enough to justify that.
Thank you Fred. I'll try to explain but it's technical:
Currently, when an "anon" user edits an article, MediaWiki adds something like this to a row in a MySQL database:
id: 1234567 userid: "34.19.215.33" article: "Egypt" change: <a diff between the new and old version> tstamp: 20051113180645
When an edit is committed, MediaWiki checks if the user that made the change has an account or not. If the user has an account it fills in the userid field with that persons choosen alias. If not it checks the IP number of the person and uses that as the userid. The solution to the problem of exposing IP:s is to proxy them via an proxy-to-IP mapping which looks something like this:
"anon1" => "34.19.215.33" "anon2" => "179.55.66.77" "anon3" => "215.108.3.2" ....
Each time an edit is comitted from an unknown IP address a new proxy-to-ip-pair is added to the mapping. MediaWiki could then simply look in the mapping for the proxy which has a certain IP. In the example above, the proxy would be "anon1". And the "userid" field in the row would contain "anon1" instead of "34.19.215.33". Preferably only a few key developers and the MediaWiki software should be allowed access to the proxy-to-IP mapping.
Checkuser would still work, but instead of returning an IP as a result could return "user: [[foobar]], [[barfoo]] and [[anon9512]] shares an IP address." Etc. There are technical solutions.
-- mvh Björn