In December 2006, Mr. Isamu Kaneko, a former University of Tokyo researcher, was fined ¥1.5 million for enabling two computer users to illegally make movies and other files available to download. The Kyoto District Court said he was guilty because he had continued to offer the peer-to-peer file-sharing software Winny, which he had developed, via his Web site since May 2002, even though he was aware it was being used for the illegal copying of copyrighted material.

On Oct. 8, however, the Osaka High Court acquitted Mr. Kaneko, pointing out that although he was aware of the possibility of copyright violations when he posted Winny on his Web site, he also warned computer users not to illegally share files.

Winny enables the anonymous exchange of documents, music, images and other files through a network of computers instead of a central server. Users designate which files can be copied, and other users search for the files on the Internet and download them free of charge. Both the lower and high court rulings deem Winny as value-neutral. Still, illegal downloading of music and images through Winny is a fact.

Winny users can expose their computers to data theft. If they download a virus-infected file, other files on the computer not designated for sharing can be instantly leaked to the Internet. This vulnerability has led some people to develop viruses targeted at secret information held by the police, the Self-Defense Forces, enterprises, etc.

Mr. Kaneko's case is the first of its kind to come before the courts in Japan: A software developer has been implicated in copyright violations that were actually committed by users of the software. He said he fears the district court ruling will deter engineers from developing new technology.

The point of the high court ruling is that the crime of assisting in copyright violations is committed only when someone's main intent is to get others to use their software for copyright violations. Improvement of copyright protection and promotion of new computer technology must go hand in hand. The government should write new rules that meet this goal.