Last modified: 2010-05-15 15:29:40 UTC
Redirects that point to pages like [[Special:Userlogout]] will log the user out. This has been used to vandalize user pages by Michael and/or Mike Church. A "confirm" button could be added to the logout page to prevent this from working.
JeLuf just made redirects to [[Special:Userlogin]] impossible. As far as I'm aware, he also put the change live already.
This doesn't stop all possibilities; [[Special:Userlogout/Yomomma]] works for instance. Re-opening.
Fixed in HEAD with Article.php 1.224