I want to know what kind of permissions are set in CMS systems like joomla, drupal, wordpress, vbulletin and others. For example a moderator, can such user perform critical actions on contents belonging to users with higher levels (Super Users, Administrators)? For example if I (Administrator) nominate a moderator and then he removes all my posts, it's a bit stupid.
Permissions works downward and not upward. So moderator cannot harm higher level users like Super Users, Administrators, but they can edit/remove content of general users (below moderator level).
Hmm...i see, so what about if the moderator wants to delete a thread started by a normal user but containing administrator posts, what will happen? Same for deleting albums started by normal users but containing images summited by admins. That kind of stuff...
the situation may vary from platform to platform but normally anything deleted by moderator stays in trash and can be retrieved by admin if they want to. to answer your question, yes, moderator can remove a thread started by a normal user, even if it has a post from admin... and admin can retrieve it later. P.S. my answer is based on general concept and may vary from platform to platform and as per the settings made by the admin.