If you google "tempAdministrator" you find a lot of people writing scripts to do admin-y things by creating a temporary admin user with a fixed password, doing the admin-y thing, then deleting the user again at the end of the script. If that sort of fsckwittage is widespread in the Windows world, it might be worth it to a hacker to randomly try login attempts in the hope of catching a machine in the act of running such a script.

Peter