Pirate Bay, Primewire, Movie4k, TorrentProject, TorrentButler and several other popular online piracy websites are currently intermittently inaccessible to certain users all over the world due to action taken by Cogent to block Cloudflare IP addresses.

Cogent is one of the biggest internet backbone providers in the world. Its thousands of commercial internet data centres help to direct web traffic for millions of users around the world every day, which is a great help to internet service providers (ISP).

Cloudflare meanwhile is an internet security firm that protects websites from distributed denial of service (DDoS) attacks, and as part of that protection, Cloudflare provides its clients' websites with the public IP addresses 104.31.18.30 and 104.31.19.30.

TorrentFreak reports that many users on a wide variety of ISPs in Europe, the US and elsewhere are currently unable to several popular online piracy websites because Cogent has blocked Cloudflare's IP addresses, in response to a court order from Spain that isn't related to copyright infringement or these sites at all.

The issue first occurred in February, and after the first block of the IP addresses, Cloudflare moved all its customers that had nothing to do with the court order, including the Pirate Bay and other online piracy sites, over to a new set of IP addresses, but now Cogent has blocked the new IP addresses 104.31.16.3 and 104.31.17.3 too.

This is not the first time that Cloudflare's customers have been blocked without being the subject of legal action. In 2015, Sky inadvertently blocked several legitimate UK websites simply because they shared an IP address with the Pirate Bay, which is blocked in the country thanks to a UK Supreme Court ruling.

Cloudflare is trying to work with Cogent to prevent mass blocking of legitimate websites, but until the IP addresses change or Cogent scales back the blocks, these websites will likely remain inaccessible on some ISPs across the world.

IBTimes UK has contacted Cloudflare and Cogent for comment and is waiting for a response.