It's a dark time for BitTorrent. These days, everyone's looking to throttle your connection, spy on what you're downloading, or even send you an ominous letter. If you use BitTorrent, you absolutely need to take precautions to hide your identity. Here's how to do that with a simple methods:
The first method is by using PeerBlock. They claim to block the MPAA and RIAA from connecting to you, but they're not very reliable, and you can still easily get caught when using PeerBlock. Similarly, while your BitTorrent client's encryption can be helpful against throttling, it doesn't always protect you, since some ISPs use more powerful methods of seeing what you're downloading that can get past basic BitTorrent encryption.
If you truly want to keep your downloading anonymous then you need to take more drastic measures. If you're worried about getting caught downloading illegal materials, use a proxy like BTGuard. It funnels all your BitTorrent traffic through another server, thus keeping your IP address hidden from anyone connecting to your BitTorrent swarm. Even if you're downloading a torrent that's being tracked, they'll see BTGuard's IP, not yours, and BTGuard doesn't keep any logs of their service, meaning they won't trace that IP address back to you.