The US District Court of California has issued a permanent injunction against the BitTorrent search engine isoHunt, forcing it to shut down in the United States. IsoHunt is expected to block all access to US visitors in response to the decision, but no action has been taken thus far.

Early 2006, the MPAA issued a complaint against isoHunt and its sister site TorrentBox, claiming that owner Gary Fung operated file-sharing services and profited from copyright infringement.

The case went on in the years that followed and two months ago the US District Court of California proposed a permanent injunction that would require isoHunt to maintain a list of banned keywords and remove torrents that match items found on it. This injunction has now become final, meaning that the site has to start filtering or close down in the US.

IsoHunt owner Gary Fung earlier told TorrentFreak that he has no faith in a filtering mechanism either. He said that such a measure “raises serious issues on the balance between freedom of speech, fair use and copyright protectionism,” as it would also filter out many torrent files that are in the public domain, or distributed with the consent of copyright holders.

Last month isoHunt chose to redirect all United States visitors to a Lite version of its website in a final attempt to prevent the search engine from having to close, but this was not enough according to the Court.

The verdict does not necessarily mean that isoHunt will be unavailable in other parts of the world. Gary Fung earlier told TorrentFreak that the ultimate measure would be to block access to visitors from the United States, which would also be sufficient to comply with the Court’s demands.

IsoHunt is not the first torrent site that has been put out of business in the United States by the MPAA. In the summer of 2007 a federal judge ruled that TorrentSpy had to monitor its users in order to create detailed logs of their activities and these were to be handed over to the MPAA.

In a response to this decision, TorrentSpy decided to block access to all US visitors instead which led to a huge drop in traffic. In 2008 TorrentSpy, once the largest torrent site on the Internet, closed its doors for good after it was ordered to pay a 110 million dollar fine.

Fung has to comply with the temporary injunction withing a day. The permanent injunction also holds for isoHunt’s sister sites TorrentBox, Podtropolis and Ed2k-it.