As heat continues to build around the controversial and contentious Stop Online Piracy Act (SOPA), one site is taking matters into its own hands to out opponents of piracy as pirates themselves.

YouHaveDownloaded.com is a site that keeps track of everything you have downloaded from file-sharing sites and torrents. The site tracks IP addresses (an identifying number given to computers attached to the Internet) that use sites such as the BitTorrent network. It then matches these IP addresses with a list of files that have been downloaded.

Logging into YouHaveDownloaded.com will do a quick cross-check of your IP with the site's database of potentially pirated downloads and show you your potentially criminal download history. More impressively, you can use the site to look up other IP addresses, torrent hashes or specific files.

At time of writing, the site has a database of nearly 54 million users (IP addresses), more than 118,000 torrents and more than 2 million files.







While this sounds like trouble for illegal downloaders, the site, designed as an open tool for anyone to use, is actually being used to bust people that support stricter online piracy laws.

SOPA is a bill designed to curb and punish online copyright violations. It has been supported by media companies, especially those in Hollywood and the film business. The bill, however, would impose tough penalties on websites for any kind of copyright infringement even if it was uploaded externally. The classic example is that a video on YouTube of Justin Bieber singing another artists song without permission would not only land Bieber in court but also put YouTube at risk of shut-down. The bill has turned into a fight between Silicon Valley and Hollywood.

YouHaveDownloaded.com, however, is showing that the bill's supporters aren't so innocent. TorrentFreak, a BitTorrent blog, recently revealed that IP addresses seemingly coming from Sony Pictures, Universal and Fox had been illegally downloading content, ZDNet reported.

An IP address in the U.S. Sony Pictures address range was reported to have downloaded music and the Conan the Barbarian film, while a US Universal IP address was allegedly caught downloading Cowboys and Aliens and the first season of the HBO show Game of Thrones. A US Fox IP address was allegedly caught downloading the J.J. Abrams film Super 8.

Now that's a sticky situation: All three companies are members of AFACT, a coalition of companies fighting copyright infringements. TorrentFreak even busted the French President Nicholas Sarkozy for illegal downloads coming from the IP address of the Presidential palace.

Of course, YouHaveDownloaded.com is not exhaustive. The site only tracks around 20% of public downloads and doesn't keep track of dynamic IP addresses, which can be used to protect online identities. Because the site uses IP addresses, it's also possible to have downloads appear on your history that you didn't actually do if you're part of a large network such as, say, Sony or Universal.

Fans of privacy need not worry, the site doesn't keep track of personal details and the odds are low that a casual user will know your specific IP address. At any rate, we're sure you're safe — you're not downloading from torrents anyways. Right?

Are you glad the site exists or is it cause for concern? Does it matter that Sony, Universal and Fox are allegedly housing pirates?

Image courtesy of Flickr, Vanessa Pike-Russell