Source: http://lifehacker.com/5617891/five-ways-to-download-torrents-anonymously
The services discussed in this post range from totally free to costing several dollars a month. The general rule is that free services are generally slower or have other restrictions, while paid ones can get you the same speeds as your regular connection would.
VPN (paid / free)
Hundreds and thousands of BitTorrent users have already discovered that a VPN is a good way to ensure privacy while using BitTorrent. For a few dollars a month VPNs route all your traffic through their servers, hiding your IP address from the public. Some VPNs also offer a free plan, but these are significantly slower and not really suited for more demanding BitTorrent users.
Unlike the other services listed in this article, VPNs are not limited to just BitTorrent traffic, they will also conceal the source of all the other traffic on your connection too. Ipredator, Itshidden and StrongVPN are popular among BitTorrent users, but a Google search should find dozens more. It is recommended to ask beforehand if BitTorrent traffic is permitted on the service of your choice.
BTGuard (paid)
BTGuard is a proxy service that hides the IP-addresses of its users from the public. The service works on Windows, Mac, Linux and as the name already suggests, it is set up specifically with BitTorrent users in mind. Besides using the pre-configured client, users can also set up their own client to work with BTGuard. It works with all clients that support "Socks V5″ proxies including uTorrent and Vuze. In addition, BTGuard also includes encryption tunnel software for the real security purists.
After these words of praise we're obligated to disclose that BTGuard is operated by friends of TorrentFreak, but we think that should be interpreted as a recommendation.
TorrentPrivacy (paid)
Torrentprivacy is another proxy service for BitTorrent users, very similar to that of BTGuard. It offers a modified uTorrent client that has all the necessary settings pre-configured. The downside to this approach is that it is limited to users on Windows platforms. TorrentPrivacy is operated by the TorrentReactor.net team and has been in business for more than two years.
Anomos (free)
"Anomos is a pseudonymous, encrypted multi-peer-to-peer file distribution protocol. It is based on the peer/tracker concept of BitTorrent in combination with an onion routing anonymization layer, with the added benefit of end-to-end encryption," is how the Anomos team describes its project.
Anomos is one of the few free multi-platform solutions for BitTorrent users to hide their IP-addresses. The downside is that it's not fully compatible with regular torrent files as Anomos uses its own atorrent format. Another drawback is that the download speeds are generally lower than regular BitTorrent transfers.
On the uTorrent Idea Bank, more than 1,600 people have asked for the Anomos protocol to be built into a future uTorrent build, making it the second most-popular suggestion overall.
Seedbox (paid)
A seedbox is BitTorrent jargon for a dedicated high-speed server, used exclusively for torrent transfers. With a seedbox users generally get very high download speeds while their IP-addresses are not shared with the public. Once a download is finished users can download the files to their PC through a fast http connection. FileShareFreak periodically reviews several good seedbox providers.