teenage software programmer in Norway was acquitted of digital piracy in Oslo yesterday in a case that has drawn close scrutiny from the entertainment industry, which has been struggling to protect DVD's, online music and other forms of media from unauthorized copying.

The youth, Jon Lech Johansen, now 19, became known as DVD Jon in 1999 after developing a program called DeCSS that enables users to unlock security codes that would otherwise prevent them from copying the digital videodiscs.

Software like DeCSS is illegal in the United States, under provisions of the Digital Millennium Copyright Act, a 1998 law that outlaws the creation and distribution of technology that enables users to skirt copyright protections on films, music and other forms of software.

Although Norway has outlawed hacking and computer piracy, the legal boundaries around DVD replication in Europe are less clear, and Mr. Johansen's case was considered a crucial test of international attitudes toward an issue that continues to frustrate Hollywood.

A three-member panel of the Oslo City Court, including a judge and two technical experts, ruled that Mr. Johansen had not broken any laws by using and distributing the software and that he was free to view DVD's he bought in any fashion he chose. Mr. Johansen has said that the software was intended to help him play DVD's he already owned on a Linux-based computer, for which DVD software had not yet been written.

"The court finds that someone who buys a DVD film that has been legally produced has legal access to the film," it ruled, as quoted by The Associated Press. "Something else would apply if the film had been an illegal, pirate copy."

Consumers' rights to legally obtained DVD's apply, the court said, "even if the films are played in a different way than the makers had foreseen."

Mr. Johansen — who had tested DeCSS on science-fiction films like "The Matrix," transferring parts of the films to his computer's hard drive — told The A.P. that he was "very satisfied" with the verdict.

The Motion Picture Association of America, an industry trade group, said in a statement: "We understand that the prosecution in Norway is reviewing whether to take an appeal, and we support that consideration. We look forward to reviewing the court's decision in greater detail."

The case was brought in January 2000, when the association filed a complaint in Norway, asserting that Mr. Johansen was guilty of economic crimes. The case went to trial in Oslo early last month.

Norwegian prosecutors, who will decide in the next two weeks whether to appeal Mr. Johansen's acquittal, contended that Mr. Johansen had removed safeguards on property owned by the film industry and left the property vulnerable to theft.