BitTorrent Tracker Blocks Thousands of ‘Infringing’ Hashes

Every day, millions of people from all around the world use BitTorrent to download and share files.

Most of these transfers are facilitated by third-party torrent trackers, which help file-sharers connect to each other.

When someone asks for information referenced by a specific torrent hash, the tracker will respond with a list of peers, if available. This is a pretty straightforward but resource-intensive process.

While there are serverless technologies such as DHT and PEX, trackers remain a central part of most people’s torrent transfers. Despite this rather crucial role, the top trackers are mostly run by volunteers and hobbyists.

OpenTrackr

OpenTrackr is one of the most used BitTorrent trackers today. The service was launched in 2015 when there was a shortage of alternatives. Since then, it has established itself as a steady player, coordinating the transfers of more than five million torrents today.

Despite handling up to 500,000 connections per second, which is good for several terabytes of daily traffic, the software runs on a single machine, an AMD Ryzen 9 Pro 3900 CPU with 2x DDR4-3200 16GB memory.

OpenTrackr’s operator, Isa, is proud of her achievements. On her own, with a little help from Patreon subscribers, she’s made the tracker a significant and reliable player in the BitTorrent ecosystem.

“It’s cool to see OpenTrackr have near daily peaks of 500,000 connections per second though, we’ve come a long way from the little Virtual Machine I spun up over 8 years ago,” Isa informs TorrentFreak.

DMCA Notices

Running a tracker is not just a technical challenge, it also comes with a legal angle. While the tracker doesn’t host any torrent or media files, not all rightsholders are pleased with the fact that bad actors can use it as well.

To accommodate these complaints, OpenTrackr accepts and processes DMCA takedown notices which allows rightsholders to list hashes that point to potentially infringing content, and have them blocked by the tracker.

If a hash is blocked, the tracker will stop assisting the communication between BitTorrent users who are interested in sharing that file.

These takedown notices are relatively rare. In 2021 and 2022 not a single DMCA notice came in, but in the past year there was some activity. On behalf of various rightsholders, anti-piracy outfit MarkScan reported 2,990 problematic hashes.

Transparency

OpenTrackr transparently discloses all takedown requests it receives. This includes the full list of hashes, which are not particularly insightful on their own.

A quick lookup reveals that these strings of numbers and letters indirectly link to torrents of a wide variety of entertainment content, including the TV series “Miracle Workers”, “Telemarketers”, and “Winning Time: The Rise Of The Lakers Dynasty.”

These hashes themselves are not directly infringing. However, a rightsholder could argue that, since OpenTrackr can block the associated torrent transfers, it must take action if problems are pointed out.

Avoiding Trouble

The notices often include duplicate hashes, which are not counted towards the total. The ones that remain are blocked indefinitely. This also applies to any future encounters.

The tracker’s operator prefers not to elaborate on the legal ramifications or potential overblocking. It’s most important for the tracker to avoid any type of problem, so processing the notices is the best option.

“Blocking a couple of thousand hashes out of the millions of active hashes is a small price to pay, the harm it would cause to so many services that rely on our tracker greatly outweighs the benefits of ignoring the notices we do get,” Isa says

This approach seems sensible. OpenTrackr is a hobby project with limited means, so its key focus is to avoid problems. According to Isa, securing the tracker’s future is most important.