A client recently got spammed and found he had 3700 new users in his wordpress blog. All spammers. This site help me clean it up quickly. http://www.scriptol.com/wordpress/mass-delete-users.php
It’s great when you can Google something and find the fix (here) in less than 30 sec.
This is a bug that WP should be fixing very soon. But good to know if you upload things with wordpress or if you are getting an error when you are uploading in WordPress.
Oh and a side note: I like the layout of WordPress 2.5. Great job guys!