Angela (beesley@gmail.com) [050412 13:43]:
Currently the only people with the necessary permissions to use CheckUser are Tim Starling (who wrote the code for this) and David Gerard (who uses it on behalf of the English Wikipedia Arbitration Committee).
I should also point out that I *barely* use it - its availability to the Ac directly is somewhat controversial, but I've some experience of net-abuse tracing and know what the results mean or don't, and I only use it when there's clearly some important issue. (Last use was to check on an apparent sock of Rienzo. Use before that was to check the zillion abusive socks in the Baku Ibne arb com case.) I get a lot of people asking me to check something casually and I have to say "no". Although if people on en: think it's relevant to an arb com case, the "Requests for clarification" section on WP:RFAr is the right place to suggest. The edit evidence had better be there, though, I'm not going on fishing expeditions.
- d.