Anti-Piracy organizations only join torrent swarms for illegal content. They also post bogus torrents to collect IPs of pirates. If Peer Guardian is going crazy, it is most likely because the torrent is a decoy to collect IPs. The data you are downloading is also most likely no good.
Also, your upload bandwidth is huge. If it is encrypted and legit, they may be trying to connect to see what you are seeding? One of these agencies does own your IPS.