Programmer Isamu Kaneko, developer of the widely used Winny file-sharing program, died Saturday night of an undisclosed illness at a Tokyo hospital, his relatives said Sunday. He was 42.
The native of Tochigi Prefecture released the program for free in 2002 when he was a University of Tokyo researcher.
Kaneko was later charged with helping Winny users illegally copy movies, games and other content and was found guilty by the Kyoto District Court in 2006.
The Osaka High Court overturned that decision and acquitted him in 2009, saying he had not intended to encourage copyright violations with the program, which enables peer-to-peer online file exchanges. The Supreme Court upheld the high court ruling in 2011, saying it was up to users to decide how to employ Winny, which it said could be used for legal or illegal purposes.
Kaneko's case was the first in Japan to address the question of whether the developer of file-sharing software can be held criminally responsible for copyright violations.