Increase in non productive posts

At the risk of sounding like a whiner myself, we seem to be spending a lot more time dealing with posters with a chip on their shoulder or an axe to grind. This has greatly affected my willingness to risk getting involved with posters. I've actually resorted to making a list of people to avoid, broken down into:

Rude
Whiners
Waste of time (those that appear to be asking people to write their site for them instead of trying to learn how to do it themselves)

This helps me avoid getting into useless debates. I was greatly encouraged when Ray deleted a post that I thought was way out of line. At times it's seems that we have been invaded by people that just want to derail the community.

I don't know what the answer is, but I think some plan should be formulated before it gets totally out of hand. Maybe an image can be created with the WA logo and something like "Post outside forum guidelines", that can be use to replace the text of offensive posts. That would act like a place holder so it wouldn't require a lot of explanation and maybe prevent the poster from feeling that they were being singled out.

Any ideas?

BTW thanks to Dave Buchholz for taking over for me in the "Web Assist not available to IE6 users" debate with Reynold. It was getting harder and harder for me to resist saying something unprofessional. :)