Anti-Torrent Activity Block
Many ISP's have recently begun to actively seek out and stop torrents from seeding, legal or otherwise. The most notorious offender is Comcast, who blocks torrents by sending a Terminate signal to one of the clients; these packets tell the Bit Torrent client to close the connection.
In the interest of being able to share legal media, such as linux iso's, you may add the following to your IP tables to have these malicious packets dropped:
iptables -A INPUT -p tcp --dport <YOUR TORRENT PORT> --tcp-flags RST RST -j DROP
Credit goes to user "James" in the comments section of a Reg newspost, which you can find here: http://www.theregister.com/2007/10/20/comcast_denies_bittorrent_busting_again/comments/