Jon Lech Johansen, 20, known in cyberspace by his nickname "DVD Jon", had pleaded innocent to the charges brought against him by the Motion Picture Association of America (MPAA).

"I'm going to celebrate by watching a few DVDs on unauthorized equipment," the Norwegian daily Dagbladet quoted him as saying after the verdict was announced.

The MPAA, which groups together studios such as Disney, Universal and Warner Brothers, had accused Johansen of creating, at age 15, the DeCSS computer program that decrypts DVDs, and distributing it on the Internet.

In his defense, Johansen argued that he developed DeCSS with two friends in order to develop a DVD player for the computer operating system Linux for his own use, not to copy DVD movies.

He has said he could not be held responsible if people used the program to make pirated copies of DVDs.

The Oslo court had already acquitted Johansen in January 2003 but the prosecutor appealed the ruling, calling for a 90-day suspended jail sentence.

"DeCSS opens the door to the mass distribution of illegal DVD copies," prosecutor Inger Marie Sunde had argued.

Hollywood was keen to win the case, as it struggles to maintain control over the use of its products. It had hoped that a guilty verdict would create a legal precedent in Norway and around the world.

In explaining the reasons for the acquittal, the appeals court said it found the DVD encryption too easy to crack.

US export laws do not allow for encryption codes longer than 40 bits. But according to the court, safe protection cannot be achieved with fewer than 64 bits.

The DVD encryption code had only 16 bits.

Johansen, who describes himself as "a self-taught information technology student", had argued that he should be allowed to do what he likes with a product he paid for.

"His aim is to defend the principle of consumer rights," Johansen's lawyer, Halvor Manshaus, said at the start of the trial.

DVD Jon has achieved cult-figure status among young websurfers, and last month landed another coup by cracking Apple Computer's online music site iTunes encryption code.

That program, which he posted on an Internet site, enables users to circumvent anti-piracy software for Apple's iTunes site and download music bought on iTunes onto their hard drive in its original format.

The user can then do as he wants with the music. The iTunes site normally allows users who buy a song for 99 cents apiece to burn it onto a CD only once, and listen to it on a maximum of three different computers.

Using DVD Jon's program, users can however copy a song and redistribute it as many times as they like.

Johansen has said that, as in the case with DVDs, his aim is to remove the obstacles that still face consumers even after they have made a purchase.

SPACE.WIRE