The operator of a popular BitTorrent search site said Monday he will likely challenge last week's landmark decision by a U.S. judge declaring such sites unlawful and no different from conventional peer-to-peer piracy services.

"We do think from our preliminary review there are a number of issues for appeal," said Ira Rothken, attorney for torrent search engine ISO Hunt, the defendant in the case.

The long-awaited decision, while not unexpected, was the first in the United States in which a federal judge found that BitTorrent search engines are an unlawful avenue (.pdf) to free movies, music, videogames and software. A contrary ruling likely would have sparked a gold rush of BitTorrent prospectors in the United States.

Targeted in the case was Gary Fung, a Canadian who operates ISO Hunt and other torrent search engines. Among other things, he argued that U.S. laws did not attach to him, and if they did, that his websites were protected under the Digital Millennium Copyright Act.

In a lawsuit brought by the Motion Picture Association of America, U.S. District Judge Stephen Wilson in Los Angeles ruled: "Defendants' technology is nothing more than old wine in a new bottle."

Fung's "intent to induce infringement is overwhelming and beyond reasonable dispute."

In terms of infringement, the judge said ISO Hunt was no different than Napster and Grokster. But he said the BitTorrent technology was far superior and "obviously increases the potential for copyright infringement."

The judge wrote that, instead of having to log into a proprietary network to download copyright files from each others' computers, "users access defendants' generally accessible website in order to download those files. And instead of downloading content files directly through defendants' website, defendants' users download dot-torrent files that automatically trigger the downloading of content files. These technological details are, at their core, indistinguishable from the previous technologies."

The MPAA has sued dozens of similar sites in the United States, resulting in settlements or default judgments. The industry group won an $111 million default judgment against TorrentSpy last year after a federal judge concluded the now-shuttered tracker hid evidence.

That case is on appeal, but Judge Wilson's ruling marks the first time that the legal merits of torrenting have been squarely addressed in the United States.

"The court's decision establishes a powerful precedent that makes clear, once again, that website operators must respect the rights of content owners and control infringement on their websites, or face liability for their actions," MPAA vice president Daniel Mandil said in a statement.

Fung, in an e-mail, said his sites should be protected by safe-harbor provisions of the copyright law, which immunize search engines from infringement liability if they promptly remove works when a rights-holder notifies them to take down infringing content.

"We are considering all options," Fung said.

Among other things, the judge said Fung has not "acted expeditiously to remove, or disable access to, the infringing material."

The judge said Fung's sites – including ISO Hunt, Torrentbox and Podtropolis – garner about 10 million hits monthly. Wilson noted that metadata for the sites included "warez" to alert search engines of the site's nature ,and that Fung was "fostering a community that encouraged – indeed, celebrated – copyright infringement."

But both Fung and Rothken said the judge got it wrong, that the site has removed thousands of infringing files upon proper request. "This alone, among other reasons, contradicts allegations that we willfully induce infringements," Fung said.

The decision came eight months after a Stockholm court ruled similarly in the movie studios and Swedish government's case against The Pirate Bay, the world's largest BitTorrent site. That case, a blend of a civil and a criminal trial, is on appeal.

That April decision calls for the jailing of the Swedish site's four co-founders. Despite a Stockholm court's orders, the site remains functional.

Fung does not face any prison time. The judge did not order Fung to shutter his sites or pay monetary damages. A hearing on those matters is scheduled Jan. 11 in Los Angeles.