While the RIAA has waged a full-on legal assault against individual file-sharers, the MPAA has instead chosen to go after individual web sites. In 2006, the motion picture industry trade group filed copyright infringement lawsuits against a number of BitTorrent sites, including TorrentSpy and isoHunt. TorrentSpy lost, thanks to its admins' willful destruction of evidence, but isoHunt is fighting back. A recent filing in the case opposes the MPAA's motion for summary judgment, arguing that isoHunt is just another search engine.

"There are hundreds of public torrent sites, some limited to a specific subject matter, others general aggregators like isoHunt, who like Google, try to cover as much of the Internet as possible," reads isoHunt's filing. "The essential functions performed at a torrent site are also performed at a comprehensive search site like Google or Yahoo!."

isoHunt then makes a series of comparisons to search engines, inviting the judge to visit Google himself to compare. The torrent site only gives users a "means to obtain content," again like Google, but not the content itself. All isoHunt does is collect data, index it, cache content, and add user-uploaded .torrent files to its database. Any actual copyright infringement occurs only on the part of the user once he or she launches a BitTorrent client.

The torrent site accuses the MPAA of playing fast and loose with the truth about the BitTorrent download process in order to build its case against. Instead of occupying a "central position or power of control," isoHunt and other torrent sites have "no meaningful existence other than through collective existence." Every function performed throughout the course of a BitTorrent download or upload is dispersed, and no single site has any "power of control."

Saying that a BitTorrent site is responsible for infringement is ridiculous, according to isoHunt. Using the odd illustration of a "Gun and Boot Store," the site's admins argue that they are no more responsible for copyright infringement than the owner of the hypothetical firearms and footwear outlet would be if someone bought a gun and pair of boots there, and subsequently robbed someone.

In making its case against isoHunt, the MPAA relies heavily on the famous MGM v. Grokster decision, in which the Supreme Court held that anyone who distributes a device with the intention that it will be used for copyright infringement can be liable for subsequent third-party infringements. That ruling is irrelevant, argues isoHunt, because it only applies to "products" and "devices," not search engines or "sites that manifest hyperlinks to dot torrent files." If that standard were used, search engines like Google or Yahoo would be liable under the MGM v. Grokster ruling if any of their search results led to copyrighted content.

It's impossible to know how the judge will rule, but, in order to prevail, isoHunt will have to convince the judge that it is the functional equivalent of a search engine. That might be a tough argument to make, since isoHunt's primary purpose is to collect an index of and links to one particular type of content. In contrast, search engines are largely data-agnostic—Google's stated intent is to index all of the world's data.

No matter which way the ruling goes, this could prove to be an important milestone for the MPAA's fight against BitTorrent sites. The MPAA has a few notches in its bedpost, but those have come from settlements which resulted in shuttered sites, or, in the case of TorrentSpy, resulted from malfeasance on the part of the defendants. And even if isoHunt convinces the judge to rule in its favor on the MPAA's motion for summary judgment, the case will still be headed for a jury trial.