If you'd like users ti be able to ban people than make something like a Tribunal
I mean, you'd be getting "cases" of reported posts (example: page of the reported post) and everyone whos a higher rank can vote on it, + and -, so it would be something like 10 - and it's a strike or something like that. Also, the cration of such page would be quite simple and the very process of reporting a post would be simple task, you'd need to post the url of the page where that post it, name of the poster and nothing else.
Because, as you can see, people don't have time to police around the forum non stop.