Four founders and financiers of filesharing site The Pirate Bay, who last year were sentenced to a year in prison, opened their appeal bid to get the verdict overturned in Stockholm on Tuesday.
In what was seen as an important symbolic victory for the movie and recording industry, the Stockholm district court in April 2009 found Fredrik Neij, 32, Gottfrid Svartholm Warg, 25, Peter Sunde, 32, and Carl Lundstroem, 50, guilty of promoting copyright infringement.
All four were sentenced to a year behind bars and ordered to pay 30 million kronor (2.7 million euros, 3.6 million dollars) in compensation to the movie and recording industry.
The four, who now all live abroad, had vowed to wage a lengthy legal battle and to take the case to the Supreme Court if necessary.
During last year's trial, the four had maintained that filesharing services can be used both legally and illegally.
One of the defence lawyers, Per Samuelsson, had argued that The Pirate Bay's services "can be compared to making cars that can be driven faster than the speed limit."
When the appeal opened in Stockholm on Tuesday, only Neij and Sunde were present, with Svartholm Warg's lawyer informing the court his client was ill and remained in his country of residence, Cambodia.
The court determined to continue hearings, but ordered Svartholm Varg to quickly present a doctor's certificate vouching for his condition.
Founded in 2003, The Pirate Bay, which claims to have more than 23 million users, makes it possible to skirt copyright fees and share music, film and computer game files using bit torrent technology, or peer-to-peer links offered on the site.
None of the material can thus be found on The Pirate Bay server itself.
In August 2009, the website, which was recently listed as one of the top 100 sites visited in the world, was pushed off line for several hours after its service provider, facing the threat of hefty fines, pulled the plug.
The Pirate Bay quickly found a new service provider, although the process has been repeated several times since then.
Currently, it is being hosted in Sweden by the pro-filesharing Pirate Party.
As early as 2006, Swedish police tried to shut down the site, raiding the company's offices several times and seizing nearly 200 servers in 2006. But the site resurfaced a few days later with servers spread among different countries.
Explore further: Brazil enacts Internet 'Bill of Rights'