Hiding/deleting posts is always a tricky issue. It's necessary, but it can create new discussions, because the users who's posts got hidden can get pretty mad.
On Facebook Pages this is solved quite nicely. If you hide a post, no one will see it anymore BUT the author. So provoking posts will not cause any trouble, but the author won't get mad, because he/she will still see the post.
This might be a nice option to have on IP.Board as well.