Japan's Computer Entertainment Suppliers Association recently conducted a study of the the world's 114 most popular sites for illegal game downloads in order to get a rough estimate on how much the industry has lost due to software piracy. The results aren't pretty: According to Andriasang's report on the group's calculations, piracy on the DS and PSP alone between 2004 and 2009 cost the worldwide games industry roughly 3.816 trillion yen, or around $41.7 billion. Join us in a "holy crap," won't you? Holy crap.

CESA noted that peer-to-peer downloads couldn't be tracked under their study, so the actual results could end up being much higher than this initial figure. We guess the industry's learned a pricey lesson about ... umm, DRM restrictions, or day-one paid downloadable content, or dedicated servers, or selling things at a negotiable price for charity.

This article was originally published on Joystiq.