Four men behind the hugely popular Pirate Bay filesharing website are to appear in court in Stockholm today for helping millions of internet users to make illegal downloads of music, films, games and software.

The Pirate Bay site, based in Sweden, has an estimated 25 million active users. Using a search engine and an internet protocol called BitTorrent, which enables the transfer of large files, the site contains information needed to download film or music files from others who have often copied them without permission.

Fredrik Neij, Gottfrid Svartholm Warg, Peter Sunde Kolmisoppi and Carl Lundström face up to two years in prison and a 1.2 million kronor (£100,000) fine if found guilty of facilitating the distribution of copyrighted material. Music and film companies have also brought a civil claim for millions of euros in compensation.

Pirate Bay has been in the sights of the music and film industries for several years as concern has grown over the level of illegal file sharing. The defendants have run the site since 2004 after it was set up a year earlier by the Swedish anticopyright organisation Piratbyrån. The website lists hundreds of thousands of “torrent” files, which link the user to content including big Hollywood films, music tracks from every leading star and software from leading companies. The site is free to use and is supported by advertising. According to information provided by Pirate Bay, in one 24-hour period this month there were 3.3 million unique users in China (22.4 per cent), 1.6 million users in the US (11 per cent) and 824,000 users in Britain (5.6 per cent).

Defenders of the four say that no copyright material is actually stored on Pirate Bay’s servers and no swapping of files takes place there. The site’s legal adviser, Mikael Viborg, has stated that because “torrent” files and trackers merely point to content, the site’s activities are legal under Swedish law.

The music and film industries disagree and hope that the case will deter illegal filesharing. Ludvig Werner, chairman of the Swedish branch of the International Federation of the Phonographic Industry, said: “Copyright exists to ensure that everyone in the creative world can choose how their creations are distributed and get fairly rewarded for their work. The operators of Pirate Bay have violated those rights and, as the evidence in court will show, they did so to make substantial revenues for themselves.”

The Pirate Bay founders insist that the site will survive whatever the outcome of the trial. They say they have set up servers in different parts of the world and that they do not know exactly where they are. Spokesmen could not be reached for comment but in a blog posting the men behind the website said in January: “The past year has been good to all of us. Next year won’t be as good, is our sad prediction. File sharing will not be very affected but our rights as human beings are being infringed all the time.”

Talking torrents

Tracker A central listing site such as Pirate Bay where users can search for music, films etc

Torrent A file that contains information about the files to be shared and about the tracker

Bit Torrent A protocol designed for transferring files, which are broken up into small chunks, making the process faster than other peer-to-peer technologies

Seed The first copy of the content to be shared. Over time many people’s PCs will hold identical copies – this is called a swarm

Leech A user who downloads but does not share his content

Sources: howstuffworks.com , Times archives