One of the co-founders of The Pirate Bay website said today that the one-year prison sentences handed down by a Swedish judge are "weird and bizarre" and insisted that the defendants "can't pay and wouldn't pay" the $3.6m (£2.4m) fine.

In a press conference held after a Stockholm court found the four defendants guilty of assisting the distribution of illegal content online that was webcast on the Pirate Bay site, Peter Sunde Kolmisoppi held up a handwritten IOU to the camera and said "that is as close as they are going to get from me".

"Even if I had any money I would rather burn everything I own and not even give them the ashes. They could have the job of picking them up. That's how much I hate the media industry," Kolmisoppi added.

Kolmisoppi said the prosecution had incorrectly tried to present the four defendants as an organised crime team, when actually he said he hardly knows his codefendant Carl Lundström.

He cited previous murder cases in Sweden in which individual crimes could not be determined when more than one defendant was tried, meaning no sentence was passed. In that context, said Kolmisoppi, the jail sentence was surprising "but they decided every one of us killed the media industry".

"It is serious to be found guilty and to get jail time, and that is a bit weird, but so bizarre that we have even been convicted at all. It is a bit unreal," he added.

Kolmisoppi urged supporters to join demonstrations in Sweden, not to protest about the sentence imposed on the codefendants but "to support the democratic process – and one not influenced by money and power which is the big issue here".

He has insisted from the start of the trial that the action was politically motivated, initiated by the Swedish government under pressure from multinational media, film and music corporations. He continued to paint a picture of The Pirate Bay as a heroic, renegade outfit, comparing the trial to the plot of the Karate Kid film and saying "in the end, we will have an epic win. We will kick ass."

The Pirate Bay site will continue to run because it was the four co-founders, and not the site itself, that were on trial, he added.

John Kennedy, the chairman and chief executive of the International Federation of the Phonographic Industry, said he expected The Pirate Bay to appeal, but insisted that the fine levied on the defendants was not just a token penalty and would be paid.

It is a third of the amount prosecutors had pushed for, but Swedish court procedure is to establish fines based on audits of a company's accounts – which hints that, contrary to the claims of the codefendants, The Pirate Bay has been generating money.

Kennedy said he "absolutely believed" that the co-founders had used overseas bank accounts to manage money made from The Pirate Bay.

"It is one thing to make money from legal music licences online, but it is quite another to say you don't make any money when you are doing so at the expense of artists, musicians and filmmakers," he added.

Other trade bodies have been quick to praise the verdict, including the Business Software Alliance and Linx, which represents the UK's internet service providers.

However, the copyright specialist Robin Fry, of commercial law firm Beachcroft, pointed out that the lawsuit may not have been successful in the UK, where copyright law is based on an act from 1906 that criminalises the use of articles designed for copying rights-protected material.

"Current legislation simply does not address these kinds of online service. Despite the Digital Britain initiative, new legislation is unlikely against a backdrop of increased calls to rebalance copyright away from the large media groups to users," said Fry.

Digital media law specialist Gregor Pryor at Reed Smith highlighted "the increased and welcome trend of protectionism" in anti-piracy cases from direct infringement on Napster to software provision in the case of Kazaa and Grokster.

"Nonetheless, as the law gets tighter, the music industry must continue to release its grip on digital content and allow compelling, innovative legal music services to grow and flourish by licensing those services on reasonable terms," Smith said.

The celebrity and technophile Stephen Fry added controversy to the debate today by commenting on the case on Twitter: "Pirate Bay not saints. But we've got to think about this rationally & sensibly. Shouting 'thief' all the time is no help. I stole in cassette age."

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