Isamu Kaneko, a very well-known software engineer and a research associate of Tokyo university, was arrested for creating a P2P software called 'Winny' which supports anonymous bulletin board and file-sharing.
Creating file-sharing software is completely legal in Japan. Therefore, police is justifying his arrest as for 'assisted two persons who illegally uploaded copyrighted materials using Winny'. This kind of stretch of the rules is a very serious threat to our freedom and rights.
Isamu was arrested May 10, 2004 in Tokyo, by Kyoto prefectural police. And still under detention without accusation.