Ebay Feedback

I have several buyers on my blocked list who have never done business with me. I blocked them solely based on the vindictive feedback they left for sellers that I know are trustworthy. I have no desire for a known problem bidder to attempt to bid on any of my auctions. For instance, just the other day I blocked a buyer for leaving negative feedbacks for sellers who did not leave a positive feedback as soon as the buyer paid, the buyer even plainly stated that in the neg he left This dolt did not seem to understand the concept that an ebay transaction is not over until the package is received by the buyer and both parties are satisfied.