Bram Cohen didn't set out to upset Hollywood movie studios. But his innovative online file-sharing software, BitTorrent, has grown into a piracy problem the film industry is struggling to handle.
As its name suggests, the software lets computer users share large chunks of data. But unlike many other popular file-sharing programs, the more people swap data on BitTorrent, the quicker it flows -- and that includes such large files as feature films and computer games.
Because of its speed and effectiveness, BitTorrent has steadily gained popularity as a tool for copying huge files, such as television shows, movies and complete CDs. Meanwhile, users have migrated away from former file-sharing top dog Kazaa in the face of entertainment industry lawsuits and a flood of bogus files.
The BitTorrent program accounts for as much as half of all online file-sharing activity, says Andrew Parker, chief technology officer of Britain-based CacheLogic, which monitors such traffic.
"BitTorrent is more of a threat because it is probably the latest and best technological tool for transferring large files like movies," said John Malcolm, senior vice president of anti-piracy operations for the Motion Picture Assn. of America.
"It is unusual, perhaps unique, in that the moment you start downloading you are also uploading," he added. "It's what makes it so efficient."
Downloading or distributing copyrighted works without permission is just as illegal with BitTorrent as it is on eDonkey, Kazaa or any other file-sharing network, said Dean C. Garfield, a top anti-piracy lawyer at the MPAA.
And BitTorrent does not conceal the Internet identities of those who share files, so they're just as vulnerable to being sued by Hollywood studios or the major record companies as other online pirates are, said Randy Saaf, chief executive of MediaDefender Inc., a Los Angeles-based anti-piracy firm.
"Anyone who uses BitTorrent and is under the illusion that they are anonymous is sorely mistaken," Malcolm said. "There is no reason why those lawsuits wouldn't include BitTorrent" users.
Cohen, 29, of Bellevue, Wash., created BitTorrent in 2001 as a hobby after the dot-com crash left him unemployed. He said the aim was to enable computer users to easily distribute content online -- not specifically copyrighted content.
"It seems pretty clear that a lot of people are actively interested in engaging in wanton piracy," Cohen said. "As far as I'm concerned, they're just pushing around bits, and what bits it is they're pushing around is not really a concern of mine. There's not much I can do about it."
BitTorrent has proved to be resistant to some of the countermeasures the entertainment industry has taken to sabotage file sharing, including the bogus versions of songs and other files uploaded to discourage piracy.
"Spoofing is very difficult on BitTorrent, if at all possible," said Mark Ishikawa, chief executive of online tracking firm BayTSP Inc. "There's no defense for this one."
Programs such as Kazaa and Morpheus allow users to link their PCs to computer networks and then run a search for the file or title they're seeking. The software then churns out a list of other computers sharing the file.
The process is simple and straightforward, which makes it relatively easy to corrupt with spoofed files.
BitTorrent software, however, can't search for anything. To find and download a file, users go to BitTorrent "seed" sites. Those websites provide a list of links to people who are offering files through BitTorrent's protocol. The program then assembles complete files from multiple chunks of data obtained from everyone who is sharing the file.
The only way to inject bogus files into the system is to fool the seed sites into posting links to them.
"It's very difficult for an interdiction company to get in the middle of that system," said Ishikawa, whose company combs file-sharing networks on behalf of Hollywood studios and alerts clients when their movies turn up on the Internet.
Some of the BitTorrent host sites, such as SuprNova.org, generate a daily list of seed files added by users. The site recently had listings for movies such as "Van Helsing" and "Wimbledon," which was not scheduled for release on DVD until Dec. 28.
Some sites offer digitized broadcasts of "The Daily Show With Jon Stewart," computer games such as "Star Trek: Klingon Academy" and "Half Life 2," e-books on the physics behind an atomic bomb, even footage of kidnap victims in the Middle East.
Downhill Battle, a Worcester, Mass.-based independent music group that has developed its own BitTorrent-based software called Blog Torrent, says the technology is much more than a tool for swapping copyrighted movies and software. (A blog is a Web journal.)