Anti-p2p groups or those with malicious intent often monitor torrent sites and harvest IP addresses. VPNs and proxies do protect against these but there are those that use blocklists with the false sense of security that they are safe.
What are Blocklists?
Block-lists are basically just a huge list of IPs that purportedly belong to anti p2p outfits or spammers. The most popular one used is i-Blocklist and used in conjunction with software such as PeerBlock or PeerGuardian to prevent you establishing connections to these IPs.
How effective are Blocklists?
Unfortunately, according to a new paper titled “The Unbearable Lightness of Monitoring: Direct Monitoring in BitTorrent,” researchers from the University of Birmingham found that 31% of the IP addresses of monitoring companies were not blocked on these block-lists. Their findings were summarized as follows: “BitTorrent users should therefore not rely solely on such speculative blocklists to protect their privacy.”
Basically if you’re willing to take the slight performance hit, blocklists do offer some protection but should be used with other protection mechanisms such as VPNs.
However, the way I see it, blocklists and VPNs are much like condoms to put it crudely. You’re not going to use a condom that fails once every 3 times and in this case as you’ll be establishing hundreds of connections, the chances of hitting an IP that is not blocked by the blocklist go up exponentially and therefore the protection afforded by a blocklist is very minimal. This seems to run contrary a previously published paper in 2007 based on a different set of blocklists (PeerGuardian, BlueTack and TrustyFiles) which came to the following findings:
1. 5 blocklist ranges encountered during the experiments contribute to nearly 94% of all the blocklist hits.
2. Most blocklisted IPs belong to government or corporate organizations.
3. Very few blocklisted IPs belong directly to content providers such as record labels.
We can only assume that anti-p2p organizations have adapted their techniques and blocklists aren’t as effective as they used to be. BolehVPN did at one point early in our business, actually did try such blocklists and found them to be miserably inaccurate often blocking legitimate traffic and not preventing notices from reaching us.
This is especially important for U.S. Internet subscribers as the six-strikes anti-piracy scheme will be rolled out later this year. The Center for Copyright Information has yet to announce the names of the companies that will do the “spying” for the six-strikes system, and when they do it will be interesting to see what data gathering methods they use.