CS, there's no need for anyone to get banned. All one has to do is abide by the posting guidelines which are right there under the "post" button (alternating with "Loose lips sink ships"). There's no reason for any "defensive" action if you are doing so.
If you believe that someone else is violating the guidelines, ask them to stop. But, be prepared to give them the same consideration you are demanding from them. If they persist, then reporting (or not reporting) the abuse to the moderators is your choice.
Aside from one local Usenet newsgroup that is heavily filtered (no crossposting and pop-up trolls are quickly relegated to the killfile), I stick to moderated forums because I've grown tired of the people that appear to enjoy anonymously stirring up conflict. But, the moderators at FR cannot read every thread, and have to rely on the participants to identify abuse.
I don't worry about the occasional slip or indiscretion (I've even requested that one of my own postings be removed), but habitual abusers become apparent pretty quickly. Most respond to a warning. Others see the writing on the wall as more and more of their postings are deleted. A few have even resorted to harassment via private FRmail, which is truly despicable.
I don't care for political correctness, either. But, indiscriminately accusing other people of committing crimes or engaging in certain sexual acts is not acceptable behavior in a civilized forum, regardless of the level of disagreement.