You are allowing Guests to make threads and posts? Turn that off in usergroup manager > unregistered users > can post threads and can reply to own threads and can reply to others thread and all that stuff there.
If you have all those things turned off, then I don't understand how they are posting images. I am unfamiliar with the album mod, but since it has to do with images, you might want to turn it off and see if that fixes things.
(Also, you may delete my thread -
http://www.walleyecentral.com/forums/showthread.php?p=1058720#post1058720. Also, that was posted in a forum which says you need to be registered in order to post in. You've got to go over all your permissions cuz they are not correct.)