BitTorrent’s Disastrous, Legendary, and Controversial Story

New Delhi, India Jul 2, 2026 ALN: Twenty-five years ago today, a young, little-known programmer by the name of Bram Cohen fired off a short message to a mailing list for peer-to-peer enthusiasts. “My new app, BitTorrent, is now in working order, check it out here,” Cohen wrote, followed by a link to his personal website.

“What’s BitTorrent, Bram?” the founder of the list asked in response.

Cohen never bothered to reply. The world would find out soon enough.

In the following years, BitTorrent quickly became the world’s most popular file-sharing app, unleashing a massive wave of piracy that upended Hollywood forever. At one point, BitTorrent was said to be responsible for a huge amount of internet traffic — some widely cited metrics peg it at half of P2P and one-third of all internet traffic in 2004. And while the entertainment industry succeeded in shutting down file-sharing systems like Napster and Kazaa, it largely failed to curtail the massive flood of BitTorrent piracy.

What stymied movie studios and record labels alike is exactly what makes the story of BitTorrent’s 25th anniversary a gripping one. There’s BitTorrent, the app that Cohen unveiled in July 2001 and which continues to attract tens of millions of monthly users to this day. There’s BitTorrent, the file-sharing protocol, which has been adopted and advanced by hackers and developers from around the world, and which helped birth an entire cottage industry of piracy websites. And there’s BitTorrent, the company cofounded by Cohen, which struggled for years to make money with its nology.

“Going into it, my plan was not to start a business,” Cohen recalls. “My plan was to start a revolution.”

This is the story of that revolution, and all that remains of it today.

Cohen started working on BitTorrent soon after leaving Mojo Nation, a startup that had ambitious plans to combine file sharing, distributed computing, and micropayments, only to shut down in 2002 without ever really getting off the ground.

Cohen helped Mojo Nation improve the efficiency of its file-sharing nology. His approach was to use something called swarming distribution: Instead of swapping large files between a few users at a time, the app would divide each file into lots of little chunks, and then allow large numbers (or swarms) of users to trade those chunks among themselves. The ethos of sharing was built into the software, insisting that users would help upload files instead of just downloading them selfishly.

Cohen was disillusioned by the failure of Mojo Nation but not ready to give up on the underlying nology just yet. “I decided to make a tool that very narrowly just did swarming distribution and nothing else, because that was a thing I knew how to do,” he says.

“My plan was not to start a business. My plan was to start a revolution.”

All this happened as P2P and file-sharing companies were facing massive headwinds. The music industry sued Napster at the end of 1999 and ultimately forced it to shut down around the time Cohen first released BitTorrent. A few months after that, the entertainment industry sued Kazaa and Grokster, followed by legal claims against Audiogalaxy, LimeWire, eDonkey, and other file-sharing systems.

Despite some significant differences in their P2P architecture, all these apps ultimately lost in court or folded ahead of a likely legal defeat. Their Achilles’ heel: They offered users a way to search for ed files and then helped them find others to trade those files with. Courts deemed this contributory infringement, pointing to the fact that the owners of these services knew exactly which files their users were trading.

BitTorrent was different. From the start, Cohen built the app without search functionality, instead relying on third-party websites for content discovery. He also didn’t run a centralized server to help users discover other BitTorrent clients to trade content with, and instead outsourced that piece of the puzzle to so-called tracker servers. Websites dedicated to BitTorrent file sharing would offer a metadata file (the torrent file) for every download, which in turn pointed users to tracker servers that matched up users to facilitate the sharing. Simply put, BitTorrent was an app to help people trade data, but its developer had no way of knowing what that data was.

That structure effectively shielded Cohen and the company he would eventually found from legal liability. To this day, BitTorrent remains the only major publisher of file-sharing software that hasn’t gotten sued by Hollywood and the major labels. However, Cohen insists that the decision to outsource content search and client discovery wasn’t primarily a shrewd legal maneuver, but a simple necessity.

After all, he was just one guy. “My hands were somewhat tied,” he says. “I was writing stuff on my own.”

Despite lacking the resources of much bigger P2P companies, Cohen’s BitTorrent app quickly gained traction in tight-knit communities looking to trade large files. Among the first adopters was Etree, an online community of jam band enthusiasts. Bands like Phish and the Grateful Dead had long encouraged their fans to trade bootleg recordings of their shows with each other in the offline world. Etree brought this idea online with the help of BitTorrent, which allowed fans to share show recordings using high-resolution audio files that were simply too big to distribute any other way.

But pirated videos were like rocket fuel. “When it started getting used for anime was when the numbers took off,” Cohen says. Granted, that early success didn’t quite measure up to the tens of millions of users apps like Kazaa were attracting at the time. “It was like, Oh, look, we’re getting a thousand downloads a day, that’s massive,” he recalls.

Things changed significantly with the emergence of major torrent sites, which allowed anyone to quickly find and download movies and TV shows. In 2002, a Slovenian high school student launched Suprnova.org, which reportedly attracted up to a million users a day before its closure in 2004. And in 2003, a ragtag group of hackers founded The Pirate Bay in Sweden. With its open embrace of illicit content and an F-you attitude toward Hollywood, the site turned into a kind of lightning rod for self-described pirates and enforcers alike.

“It was so fast that we initially thought something was broken.”

While these sites quickly became household names, countless others sprung up all across the globe in their shadows. Some catered to specific interests like anime, porn, or ’70s B movies, while others simply welcomed everyone and everything. And while holders were able to shutter some sites, others survived, or reemerged under different names or domains. Plus, all those lawsuits generated countless headlines, effectively promoting BitTorrent to new audiences. By 2004, BitTorrent traffic exploded.

The surge of interest didn’t just alarm rightsholders. It also put some significant strain on BitTorrent’s infrastructure, including the tracker servers that helped users discover each other. One popular tracker, Denis.Stalker.H3Q.com, was run by a trio of German hackers associated with the local Chaos Computer Club.