Hi. I'm a mod for Coupon Connection and OneWorld. Moderators are able to delete posts and threads in our own forums. When I see spam in someone else's forum, I see the "report post" icon. I find my fellow mods are very responsive, and delete the post the next time they are online. When there is no moderator for a forum, I still use the "report post" icon. I believe that the message then goes to Randy's IT guys. They have been awesome about deleting such drivel.

Each of the forums you mentioned has a moderator. Have you tried reporting each post? It's a great way to help the forum moderators out.