Peer Block {jdjackson}

PeerBlock blocks "known bad" computers from accessing yours, and vice versa. Depending on the lists you have it set up to use, you can block governments, corporations, machines flagged for anti-p2p activites, even entire countries! Whether you're sharing files with Bittorrent or just surfing the web, PeerBlock can help protect you from the bad guys.

Posted with the help of ORB666, all credit goes to him.