PeerGuardian

Website/Download: http://phoenixlabs.org/pg2/
License: Freeware
OS: Windows Mac
Latest Version: 2.1
Publisher's description:
PeerGuardian and PeerGuardian 2 are free and open source programs developed by Phoenix Labs. They are capable of blocking incoming and outgoing connections based on IP blocklists. Their purpose is to help protect the user's privacy from organizations such as the RIAA and MPAA while using filesharing networks such as FastTrack and BitTorrent[citation needed]. The system is also capable of blocking advertising, spyware, government and educational ranges, depending upon user preferences.