The four men behind the popular file-sharing site The Pirate Bay go on trial Monday in Stockholm, accused of helping millions of Internet users illegally download protected movies, music, and computer games. Charges were made early last year by a Swedish prosecutor with conspiracy to break copyright law and related offences.

In order to convict the four defendants, the prosecutor has to prove that copyright infringements have actually been committed in the first place, not just as conjecture, but in real cases where the proof will hold up in a court of justice. Companies including Warner Bros., MGM, Columbia Pictures, 20th Century Fox Films, Sony BMG, Universal and EMI are also asking for damages of more than 100 million crowns ($12 million) to cover lost revenues.

The Pirate Bay website hosts BitTorrent tracker files, and claims to be the world's largest: in February 2009, they reported 22 million simultaneous users. The defendants, Fredrik Neij, Gottfrid Svartholm Warg, Peter Sunde Kolmisoppi, and Carl Lundström, face up to two years in prison and a fine of 1.2 million kronor ($143,529) if convicted of being accessories and conspiracy to break Swedish copyright law.

The case focuses on dozens of works that the prosecutor claims were downloaded illegally, including music by the Beatles, Robbie Williams and Coldplay and movies such as "Harry Potter and the Goblet of Fire" and season one of the TV show "Prison Break."

The trial is expected to last for 13 days. But no one expects the case to be settled in the district court. A final verdict should not be expected until five years from now, Marianne Levin, a lawyer and expert in intellectual-property law, said in an interview for a specialized publication in Sweden.