One hundred altruistic pirates are responsible for two-thirds of BitTorrents that infringe copyright, according to research.
BitTorrent is a peer-to-peer technology that allows files to be shared over networks. Large files such as movies can be downloaded concurrently from hives of thousands of users, called seeds, who all retain identical copies of the downloaded material.
BitTorrent files, similar to shortcut links, are posted onto sites that, along with tracker servers, point downloaders to the location of seeds. Once a file is uploaded it can be spread throughout the hive. The most popular and trusted torrents often have the largest amount of seeds, because users generally only retain and seed high-quality downloads.
The research, run by university researchers from Germany, the United States and Spain, found that the 100 top pirates are responsible for 67 per cent of copyright content illegally shared over BitTorrent.
Of these, about 20 use private trackers — exclusive servers for users that have high-seed counts — and are responsible for nearly a third of illegal downloads of copyright material.
The top prolific pirate uploaders may also be paid for their work, the report (PDF) found, because they promote websites within their BitTorrent files.
"Our examination revealed that these publishers often include a promotional URL in the text box of the content web page and some of them use other … techniques," the report read.
"Overall, these profit-driven publishers publish 26 per cent of the content and receives 40 per cent of the downloads. Therefore, the removal of these few publishers would have a dramatic impact on the demographics of the current BitTorrent open ecosystem."
About 50 per cent of prolific pirates are "altruists", according to the report, because they spend resources on seeding torrents without embedding promotional material.
"We did not discover any interesting or unusual behaviour in torrents published by regular publishers and thus conclude that they behave in an altruistic manner.
"There are some good citizens that dedicate their resources to share content with a large number of peers in spite of the legal implications this activity may have."
Many also shirk downloading torrent files — called leeching — to focus on uploading and spreading their own work, which the researchers said reinforces the notion they are altruistic.
Around 30 per cent of the most prolific pirates are a mix of anti-pirate companies or malicious users which seek to disrupt or damage the BitTorrent community.
Organisations such as the Australian Federation Against Copyright Theft (AFACT) intercept pirate torrents to identify downloaders, and some upload fake torrents to destabilise the sharing communities.
"This means that these publishers sustain a continuous poisoning-like index attack against BitTorrent portals that based on our results affects [up] to millions of downloaders," the report said.
Up to a quarter of BitTorrent downloaders will fall for scams by anti-pirate agencies and malicious users, meaning they may receive anti-pirate propaganda or infected or broken files.
AFACT has been embroiled in a legal fight with internet provider iiNet after it claimed online copyright infringement was rampant on the internet service provider's network and sought restitution. iiNet won the case, which is currently at the appeal stage.