(FORTUNE Magazine) – Jon Johansen didn't know what he was getting into. A year ago the Norwegian 16-year-old wanted to play DVDs on his Linux-based computer, so he and a few friends proceeded to crack the DVD encryption. In November, they posted their descrambler online--and the movie industry instantly struck back, threatening lawsuits against anyone who distributed the code. At one point Norwegian police hauled Johansen in for questioning. "I realized it might lead to some problems, perhaps just threatening e-mails, but nothing like this," he says. This summer a U.S. judge ruled in favor of the studios, claiming the descrambler, DeCSS, was a "common-source outbreak epidemic." Johansen, who wasn't formally named in a suit, has become the global poster boy in the file-sharing wars. But for the studios he's a symbol of their darkest fears: People could soon swap movies online the way they now trade MP3s.

--C.T.