I personally think the bar for reporting posts is a little low.
To report a post you should have a post count in the thousands, at least.
This does not disenfranchise lurkers or other small-time posters, since there are a number of high-post count forum members actively reading through the forums who regularly tag bad posts -- even in threads in which they do not participate.
It does, however, prevent losers from spamming the forum with this form of graffiti.
At the risk of advocating a kind of up-vote system...
Maybe there could be an "unreport" button too, and the post is unreported or reported based upon the total post counts of the users that clicked it.
/loser with 100 posts clicks report: net report = -100
/user with 4000 posts clicks unreport: net report = +3900
So even if a high-poster (like the occasional lounge bunny -- no names here) reports a post, a couple of unreports would permanently fix it?