File Sharing's New Face

R. A. Hettinga rah at
Fri Feb 13 08:21:52 PST 2004


The New York Times

February 12, 2004

File Sharing's New Face


AFTER working for a parade of doomed dot-com startups, a young programmer
named Bram Cohen finally got tired of failure.

"I decided I finally wanted to work on a project that people would actually
use, would actually work and would actually be fun," he recalled.

 Three years later, Mr. Cohen, 28, has emerged as the face of the next wave
of Internet file sharing. If Napster started the first generation of
file-sharing, and services like Kazaa represented the second, then the
system developed by Mr. Cohen, known as BitTorrent, may well be leading the
third. Firm numbers are difficult to come by, but it appears that the
BitTorrent software has been downloaded more than 10 million times.

And just as earlier forms of file-sharing seem to be waning in popularity
under legal pressure from the music industry, new technologies like
BitTorrent are making it easier than ever to share and distribute the huge
files used for video. One site alone,, routinely offers hundreds of television programs, recent
movies and copyrighted software programs. The movie industry, among others,
has taken notice.

What Mr. Cohen has created, however, seems beyond his control. And when he
was developing the system, he said, widespread copyright infringement was
not what he had in mind.

Rather, he was intrigued by a problem familiar to many Internet users and
felt acutely by friends who were trading music online legally: the
excruciating wait while files were being downloaded.

"Obviously their problem was not enough bandwidth to meet demand," Mr.
Cohen said in an interview at a Mexican restaurant near his home in
Seattle. "It seemed pretty clear to me that there is a lot of bandwidth out
there, but it's not being used properly. There's all of this upload
capacity that people aren't using."

That was the essential insight behind BitTorrent. Under older file-sharing
systems like Napster and Kazaa, only a small subset of users actually share
files with the world. Most users simply download, or leech, in cyberspace

BitTorrent, however, uses what could be called a Golden Rule principle: the
faster you upload, the faster you are allowed to download. BitTorrent cuts
up files into many little pieces, and as soon as a user has a piece, they
immediately start uploading that piece to other users. So almost all of the
people who are sharing a given file are simultaneously uploading and
downloading pieces of the same file (unless their downloading is complete).

The practical implication is that the BitTorrent system makes it easy to
distribute very large files to large numbers of people while placing
minimal bandwidth requirements on the original "seeder." That is because
everyone who wants the file is sharing with one another, rather than
downloading from a central source. A separate file-sharing network known as
eDonkey uses a similar system.

For Mr. Cohen, BitTorrent was always about exercising his brain rather than
trying to fatten his wallet. Unlike many other file-sharing programs,
BitTorrent is both free and open-source, which means that those with enough
technical know-how can incorporate Mr. Cohen's code into their own programs.

While writing the software, "I lived on savings for a while and then I
lived off credit cards, you know, using those zero percent introductory
rates to use one credit card to pay off the previous card," Mr. Cohen said.

The first usable version of BitTorrent appeared in October 2002, but the
system needed a lot of fine-tuning. Luckily for Mr. Cohen, he was living in
the Bay Area at the time and his project had attracted the attention of
John Gilmore, the free-software entrepreneur, who had also been one of the
first employees at  Sun Microsystems. Mr. Gilmore ended up helping Mr.
Cohen with some of his living expenses while he finished the system.

"Part of what matters to me about this is that it makes it possible for
people with limited bandwidth to supply very popular files," Mr. Gilmore
said in a telephone interview. "It means that if you are a small software
developer you can put up a package, and if it turns out that millions of
people want it, they can get it from each other in an automated way."

 BitTorrent really started to take off in early 2003 when it was used to
distribute a new version of Linux and fans of Japanese anime started
relying on it to share cartoons.

It is difficult to measure BitTorrent's overall use. But Steven C. Corbato,
director of backbone network infrastructure for Internet2, the high-speed
network consortium, said he took notice in May. "We started seeing
BitTorrent traffic increase right around May 15, 2003, and by October it
was above 10 percent of the traffic," he said.

Data for the week of Jan. 26, which Mr. Corbato said was the latest
reliable information, showed that BitTorrent generated 9.3 percent of the
total data traffic on Internet2's so-called Abilene backbone, which
connects more than 200 of the nation's biggest research universities, in
addition to laboratories and state education networks. By contrast, no
other file sharing system registered more than 1 percent of the traffic,
though Mr. Corbato said his network might be underreporting the use of
those other services.

Just a few months ago, however, that success still had not translated into
dollars for Mr. Cohen.

"This past September I had, like, no money," he recalled. "I was just
scraping along and doing the credit card thing again."

But unknown to Mr. Cohen, BitTorrent was serving as a job application. Out
of the blue, he heard from Gabe Newell, the managing director of Valve
Software, based in nearby Bellevue, Wash. Valve is developing what gaming
experts anticipate will be a blockbuster video game, Half-Life 2, but it is
also creating an online distribution network that it calls Steam. Because
of Mr. Cohen's expertise in just that area, Valve offered him a job. He
moved to Seattle and started work in October.

 "When we looked around to see who was doing the most interesting work in
this space, Bram's progress on BitTorrent really stood out," Mr. Newell
said. "The distributed publishing model embedded in BitTorrent is exactly
the kind of thing media companies need to build on for their own systems."

All along, Mr. Cohen had accepted donations from BitTorrent users at his
Web site,, but the sum had been minimal. In October,
however, Mr. Cohen's father prevailed on him to ask a bit more directly.
Now, Mr. Cohen said, he is receiving a few hundred dollars a day.

"It's been a pretty dramatic turnaround in lifestyle in just a few months,
with the job and the donations coming in," Mr. Cohen said. "It's nice."

According to survey data from the Pew Internet and American Life Project,
file sharing is on the wane, apparently as a result of the music industry's
legal offensive. Last May, 29 percent of adult Internet users in the United
States reported that they had engaged in file sharing; that figure dropped
to 14 percent in a survey conducted in November and December. Nonetheless,
the ranks of the BitTorrent faithful - whether anime fanatics, Linux users,
Deadheads or movie pirates - appear to be growing. And some are quite
thankful to Mr. Cohen.

"I think Bram is going to be like Shawn Fanning in terms of the impact this
is going to have," said Steve Hormell, a co-founder of, a
music-trading site that predates the file-sharing phenomenon, referring to
the inventor of the original Napster service. "It is a bit of paradigm
shift and I can't stress the community aspect of it enough. You have to
give back in order to get. Going back 15 years, that's what the Internet
was all about until the suits came along."

Not surprisingly, the movie industry is not amused. "BitTorrent is
definitely on our radar screen," Tom Temple, the director for Internet
enforcement for the Motion Picture Association of America, said in a
telephone interview. While the association first became aware of the
technology about a year ago, BitTorrent's surging popularity prompted the
group to start sending infringement notices to BitTorrent site operators in

"We do have investigations open into various BitTorrent link sites that
could lead to either civil or criminal prosecution in the near future," Mr.
Temple said.

For his part, Mr. Cohen pointed out that BitTorrent users are not anonymous
and that their numeric Internet addresses are easily viewable by anyone who
cares. "It amazes me that sites like Suprnova continue to stay up, because
it would be so easy to sue them," he said. Using BitTorrent for illegal
trading, he added, is "patently stupid because it's not anonymous, and it
can't be made anonymous because it's fundamentally antithetical to the

That said, Mr. Cohen is not in the nanny business.

"I'm not going to get up on my high horse and tell others not to do it
because it's not my place to berate people," he said. "I just sort of watch
it with some amusement."

R. A. Hettinga <mailto: rah at>
The Internet Bearer Underwriting Corporation <>
44 Farquhar Street, Boston, MA 02131 USA
"... however it may deserve respect for its usefulness and antiquity,
[predicting the end of the world] has not been found agreeable to
experience." -- Edward Gibbon, 'Decline and Fall of the Roman Empire'

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