Who built Kazaa, and why did it survive Napster's shutdown?
Kazaa Media Desktop appeared in March 2001, released by Consumer Empowerment, a Dutch company run by Niklas Zennstrom of Sweden and Janus Friis of Denmark. The software sat on top of FastTrack, a peer-to-peer protocol written by the Estonian programmers of BlueMoon Interactive, a team headed by Jaan Tallinn, who had sold the technology to Zennstrom and Friis.
The timing was everything. Napster ran every search through its own servers, so when a United States court ordered those servers switched off in 2001, the whole network went dark in a single move. FastTrack had no center to switch off. It promoted well-connected machines on the network to supernodes, each holding a searchable index of files on the peers around it and answering their queries. Shut one down and the network simply routed around it.
That one design decision is why Kazaa, rather than any of the dozen other clients launched in 2001, inherited the audience Napster left behind. It also set the legal problem that would define the next five years: there was no plug to pull, so the recording industry had to go after the company, the users, or both.
How big did Kazaa get, and what did it install on your computer?
In late May 2003, Kazaa Media Desktop passed ICQ to become the most downloaded piece of software tracked by CNET's Download.com, with 229,513,316 cumulative downloads. That spring the FastTrack network was peaking at close to four million people online at the same moment, which made it the largest file-sharing network in the world by a wide margin.
It was free because it was not really free. The installer came bundled with advertising software, and depending on the version, with tracking components that most users never read about in the license agreement. Advertising paid for the network. For a reader in 2002 that trade looked reasonable: albums for nothing, in exchange for pop-ups.
Quality control did not exist. A file labeled as a hit single might be the song, a badly encoded copy, a different track entirely, or a virus. The Recording Industry Association of America turned that weakness into a weapon, flooding the network with corrupted decoy files so that finding a clean copy took several tries. Sorting real results from fake ones became a skill of its own, and it pushed experienced users toward BitTorrent and LimeWire well before the courts caught up.
Why did the record labels sue tens of thousands of ordinary people?
On September 8, 2003, the Recording Industry Association of America started suing individual file sharers. One of the first defendants was Brianna LaHara, a twelve-year-old living in a Manhattan housing project, who had just started the seventh grade. Her family settled within days for $2,000.
"I am sorry for what I have done. I love music and don't want to hurt the artists I love," LaHara said in a statement carried by TechNewsWorld in 2003. Her mother added that the family had not understood the software was illegal. The case did more to shape public opinion than any of the thousands that followed.
The strategy was never to sue everyone. It was to make the risk feel personal. Settlement demands typically landed around $3,000, far less than fighting would cost, so almost nobody fought. The Hollywood Reporter counted roughly 35,000 lawsuits against individuals by the time the recording industry stopped filing them in late 2008 and turned to working with internet providers instead. The campaign changed behavior and cost the labels years of goodwill doing it.
What did the Australian court decide about Sharman Networks?
By 2002 the Kazaa application belonged to Sharman Networks Limited, a company incorporated in Vanuatu and run from Sydney by Nikki Hemming, with the FastTrack protocol licensed in from Joltid Ltd. Hemming said the Vanuatu incorporation was for tax reasons. The entertainment industry read it as a deliberate effort to put the company out of reach of any single court.
It did not work. In Universal Music Australia Pty Ltd v Sharman License Holdings Ltd, decided in the Federal Court of Australia on September 5, 2005, Justice Murray Wilcox found that the respondents had "authorised" Australian users to "make a copy of the sound recordings" and to "communicate the recordings to the public". The finding turned on knowledge: Sharman knew what the network was mostly used for, had technical means available to filter copyrighted files, and chose not to use them because filtering would have cut its own revenue.
On July 27, 2006, Sharman Networks settled with the recording industry worldwide for $115 million, with more than $100 million of it going to Universal Music, Sony BMG, EMI and Warner Music. Sharman also agreed to turn Kazaa into a licensed service and to build in measures against piracy. "Kazaa was an international engine of copyright theft which damaged the whole music sector and hampered our industry's efforts to grow a legitimate digital business," said John Kennedy, then chief executive of the IFPI, in Billboard in 2006.
Who owns Kazaa now?
Nobody is operating it. After the settlement the Kazaa name passed to Brilliant Digital Entertainment, the Sydney company run by Kevin Bermeister, which relaunched Kazaa in July 2009 as a paid subscription service with tracks licensed from the four major labels. In October 2010 the service was taken over by Atrinsic, a New York digital marketing firm, which put out a Kazaa app for the iPad in March 2011.
The second life lasted under two years. Atrinsic filed for Chapter 11 bankruptcy protection in the Southern District of New York on June 15, 2012, saying it had shut down its direct-to-consumer subscription business and could not raise more working capital. The Kazaa site stopped serving anything that August. No maintained Kazaa client has shipped since, no company sells or supports the software in 2026, and the name never got the second life that the LimeWire brand did.
Anything offered today as a Kazaa download is a copy of abandoned 2000s software, shipped by somebody with no connection to Sharman Networks, Brilliant Digital Entertainment or Atrinsic, and usually with the original adware still attached. There is no legitimate version to install.
What happened to the technology behind Kazaa?
It got a knighthood instead of a sentence. Niklas Zennstrom, Janus Friis and the Estonian engineers who wrote FastTrack reused the same supernode architecture in 2003 to route voice calls, and called the result Skype. Microsoft bought it in 2011 and retired it on May 5, 2025, moving the remaining users to Teams.
Jaan Tallinn, who headed the team that wrote the protocol, went on to fund research into risks from artificial intelligence. The code that was treated as a criminal instrument when it moved MP3 files was treated as a breakthrough when it moved voice packets. The architecture never changed. Only the payload did.
Frequently Asked Questions
Does Kazaa still exist in 2026?
No. Kazaa stopped being a free file-sharing network after Sharman Networks settled with the recording industry in July 2006, and the licensed Kazaa subscription service that replaced it went offline in August 2012. No Kazaa client has been maintained since then, and no company operates the service in 2026.
When did Kazaa shut down?
Kazaa shut down in two stages. The original file-sharing operation ended with the $115 million settlement of July 27, 2006, and the licensed music service that carried the Kazaa name stopped in August 2012, two months after its operator Atrinsic filed for Chapter 11 bankruptcy on June 15, 2012.
Who created Kazaa and the FastTrack protocol?
The FastTrack protocol behind Kazaa was written by the Estonian programmers of BlueMoon Interactive, a team headed by Jaan Tallinn, who sold it to Niklas Zennstrom and Janus Friis. The two launched Kazaa Media Desktop in March 2001 through their Dutch company Consumer Empowerment, then sold the application to Sharman Networks in 2002.