Most file-sharing programs aren't the most upstanding citizens of the computing world. Yes, the entertainment industry hates them for the way they're used to download movies and albums without paying -- but many of these programs also fail to treat their own users well, often installing an unadvertised, unwanted load of advertising and spyware.
BitTorrent is different. This free, open-source program offers a spyware- and nuisance-free installation. And while it is certainly handy for downloading movies and other copyrighted material for free, it's also increasingly used to distribute software and entertainment legally.
This makes BitTorrent (www.bittorrent.com
) not only a fascinating test case for legal experts, but it also looks a lot like the logical fusion of peer-to-peer file-sharing and traditional downloading. It's too robust to stamp out with lawsuits, but too effective not to adopt for commercial use.
BitTorrent works by enlisting everybody into the file-distribution process. A BitTorrent download starts when you click on a ".torrent" link on a Web page, in an e-mail or some other document. That link gets handed off to your BitTorrent program, which follows that link to a "tracker" computer. (BitTorrent doesn't have any file-search capability built in; you must find these .torrent links yourself.)
The tracker, in turn, points your copy of BitTorrent to a random grouping of other BitTorrent users who have the file you want. Your copy then starts downloading, assembling all these disparate chunks into a perfect copy of the original. But once you have part of the file on your computer, BitTorrent also begins uploading that to other people who come looking for it.
This uploading continues until you close the BitTorrent program.
The net effect of this is a vast increase in the resources available to distribute a file -- instead of the limit being one Web site's own Internet connection, you can theoretically put the entire bandwidth of the Internet to work. The original distributor of the file needs to upload it only once, after which everybody else takes care of the work -- and as more people download it, the torrent picks up speed.
This approach is overkill for a three-minute song, but for a 30-minute sitcom or a two-hour movie, it's highly effective.
As a result, the Motion Picture Association of America is less than thrilled about that particular use. It has taken tracker sites to court for their role in pointing users to movie downloads. As part of one settlement, it took over one such site, LokiTorrent.com, and turned it into an online billboard warning users of the legal risks they faced.
But the Washington-based lobby hasn't sued BitTorrent's developer, Bram Cohen of Bellevue, Wash., nor has it gone after individual BitTorrent users. (Full disclosure: For research purposes, I've used BitTorrent to grab two episodes of "The Simpsons" and Jon Stewart's famously combative "Crossfire" appearance.)
"There are good and bad uses for this technology," said David Green, the MPAA's vice president for technology and new media. The association is instead focusing on the people who have gone out of their way to help others download movies -- "the people who are bringing together the people who want infringing material," as he put it.
This represents a shift from previous practices, in which the MPAA, the Recording Industry Association of America (news - web sites) and other groups have tried to have entire products -- for example, the first Diamond Rio MP3 player or the networked ReplayTV (news - web sites) video recorder -- taken off the market.
One reason for this change of heart may be that in BitTorrent, unlike many other file-sharing programs, legitimate use doesn't amount to a token minority. It's central to this program's existence.
Developers of versions of the Linux (news - web sites) operating system were some of the first to jump on BitTorrent as a way to ship out vast amounts of data. A Linux distribution can easily span four CD-ROMs; instead, companies such as Red Hat offer BitTorrent downloads of their work.
Independent musicians can also use BitTorrent to provide free samples. The Web site of the South by Southwest music festival (2005.sxsw.com/
geekout/sxsw4pod/) uses BitTorrent to offer a 2.6-gigabyte compilation of songs by artists playing at this Austin event. (In an unplanned demonstration of how BitTorrent doesn't always function at top speed, that torrent was more of a glacier Tuesday night, with too few users to serve up bits of the file.)
BitTorrent hasn't been the most approachable program ever, but the 4.0 version released Tuesday offers a far cleaner interface: Simple play/pause buttons start and stop downloads, while a slider control regulates your uploading bandwidth.
Rough edges still lurk behind that front end, though. The Windows installer doesn't ask where you want the program parked on your system, and the dialogue box to select a download directory suffers from an awkward, multi-pane perspective of your file system. (A Linux version is also provided, with an earlier version available for Mac OS X (news - web sites).)
Since BitTorrent is open-source, you can also use other programs that incorporate its code to perform the same task -- or entirely different functions. For example, a Mac program with the unlikely name of Goombah (www.goombah.com
) uses torrent file-transfers to analyze your iTunes music library, then recommend other songs.
The MPAA may be able to drive BitTorrent movie downloads into what Green called "the dark corners of the Internet," but this program isn't going to go away. It might, however, be just what movie studios and record labels need to market and distribute their own content efficiently on the Web.