Its been pretty busy on the digital music front of late, with the U.S. Supreme Court declining to hear a case that might have forced Internet Service Providers to expose the identities of people sued by the recording industry. Most of these lawsuits are now filed against John Doe. The decision was a big blow to the Recording Industry Association of America, the industrys lobbying group. The RIAA downplayed the news, however, saying that the courts decision will not deter our ongoing anti-piracy efforts. The John Doe litigation process we have successfully utilized this year continues to be an effective legal tool.

Despite the music industrys tireless efforts to litigate away the file-sharing threat, a new group of peer-to-peer (P2P) programs is replacing the older, lawsuit-targeted modelsand none are growing as fast as a program called BitTorrent. According to CacheLogic, a P2P traffic-monitoring company based in Cambridge, England, more data is now being transferred via BitTorrent than by any other P2P network worldwideand its share is rising.

BitTorrent was created three years ago by programmer Bram Cohen, who came up with the idea while working on an open source content-distribution project called Mojo Nation. BitTorrent relies on a concept called swarming distribution, in which files such as movies and songs arent transferred in one piece from one persons hard drive to another. Rather, small bits of a file are pulled from many users hard drives and reassembled by the program on the requesters computer.

Say you wanted to download the film Donnie Darko. Youd find a BitTorrent-related website such as Filesoup or TVTorrents and click on the movies link. Instead of that click facilitating a transfer of the file from one users computer to your own (how Kazaa and others work), BitTorrent swarms its network to pull small pieces of the file from sometimes thousands of computers. This enormous collection effort is invisible to the usertheres no assembly required, you might say. The only difference the user would notice is that the file arrives a lot faster than on most file-sharing services, since it comes as a collection of short bursts instead of in one laborious transfer. Its as if a thousand people put together a jigsaw puzzle, with each person knowing exactly where his or her piece went.

And unlike Kazaa, or Napster before it, BitTorrent has no central interface through which users can search for files. Programming a good search interface was pretty tough, says Cohen, who lives in the Seattle area. I decided to make it someone elses problem. As a result, a burgeoning network of websites provides the list of files available. Instead of calling up a program like Kazaa and typing in Planets West to find that bands music, a BitTorrent user searches through BitTorrent-related sites. Once the desired file is found, the user starts downloading it from multiple other users at once. Another interesting feature of BitTorrentas soon as you download a piece of a file to your computer, that piece becomes available for others to download as well. This element increases the size of the network, and the speed of downloading.

BitTorrents growing popularity, and the way in which it works, may bode ill for the entertainment industrys efforts to crack down on file trading. Perhaps most troubling for Hollywood: BitTorrent is optimized to handle large files, says Jim Graham, a spokesperson for BayTSP, a firm that monitors and analyzes peer-to-peer networks. And thats code for movies and software. Most P2P services allow individuals to swap files with other individuals. If the sought-after file is a 2-gigabyte movie, it can take an awfully long time to upload from an individuals computer for transfer. With BitTorrent, each user only has to upload a small segment of a file. This approach not only takes far less time, it is also less prone to encountering an error along the way–such as a user turning off his computer mid-transfer.

The music and movie companies have yet to launch an anti-BitTorrent effort on the scale of the wars waged against Napster and Kazaa. But dont expect the industry to let BitTorrent go unlitigated for much longer. When asked via e-mail if the RIAA had any plans to go after the service or had a message for its creator, a spokesperson for the group said only, We don’t discuss (or handicap) our future enforcement strategies or plans.

According to Cohen, the BitTorrent software has been downloaded more than 10 million times. While the predominant use of the program thus far has been for swapping copyrighted material, legitimate uses of swarming distribution are appearing as well. Game companies are using BitTorrent, says Cohen, to distribute demos ahead of an official release to generate interest in a title. Given the lack of a searchable interface, BitTorrent isnt optimized for wide-spread illegal distribution. Its poorly suited to be a warez tool, says Cohen (warez is slang for copyrighted digital content illicitly distributed online). You have to be very obvious. Its easy to track you down. The website you download from is quite visible. The lack of BitTorrent-related busts to date may be a result of the RIAAs interest being elsewhere. But with the advantages BitTorrent technology brings to file transfers, expect to see content companies co-opting it in some form.