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