Andorin (1624303) writes "It's common knowledge that the majority of files distributed over BitTorrent violate copyright, though the exact percentage is unclear. The Internet Commerce Security Laboratory of the University of Ballarat in Australia has conducted a study and found that 89% of files examined were in fact infringing, while most of the remaining 11% were ambiguous but likely to be infringing. Ars Technica summarizes the study: "The total sample consisted of 1,000 torrent files—a random selection from the most active seeded files on the trackers they used. Each file was manually checked to see whether it was being legally distributed. Only three cases—0.3 percent of the files—were determined to be definitely not infringing, while 890 files were confirmed to be illegal. " The study brings with it some other interesting statistics; out of the 1,000 files, 91 were pornographic, and approximately 4% of torrents were responsible for 80% of seeders. Music, movies and TV shows constituted the three largest categories of shared materials, and among those, zero legal files were found."
Link to Original Source