Dealing with "reported" posts  is a mod/admin tier job. Reported posts are brought to the attention of mods, who then must deal with the problem, lest they be plagued by the message for all forum eternity. A mod or admin can deal with the report in any way they choose; to tempban or permaban the perpetrator, or to treat it as a false positive and take no action.

The reported posts don't just happen. A post can (usually) be reported by any old user; heck, I could report any post I wanted. The problem is, if I go around pissing mods off by reporting posts with nothing wrong, they see a pattern and...

* Silvertie goes sailing out window, defenestrated by banhammer

that happens. The idea is to use the report post button to flag inappropriate content. However, here in the paradigm, nobody posts anything inappopriate, and if they do, nobody seems to care enough to report it; hence the novelty of seeing a reported post.

Also note that the report is shared amongst all mods and admins; if one deals with it, the report is not shown to other forum staff.