Despite the movement to make science more “open,” academic journals still wield a fair amount of control over scientific progress—some charge as much as $32 per paper, locking knowledge away unless you can afford the price of admission. Alternatives to traditional journals have sprouted up all over the place, with scientists publishing in pre-print archives, or anonymously criticizing research and forcing retractions on forums.

Now, the main URLs for one important outlet of open access research papers have basically disappeared from the internet, thanks to pressure from publishing giants.

Sci-Hub, sometimes called “The Pirate Bay of science,” is the brainchild of Alexandra Elbakyan, who founded the site in 2011 while she was a graduate student in Kazakhstan. Sci-Hub was her way around the paywalls at journals, which have insisted that their high prices are necessary. Elsevier, one of the largest academic publishers, told Motherboard in 2016 that “pricing correlates to impact factor”—the journal’s yearly average citation number—and that they “operate a value-based system which reflects the value that we provide.”

On February 3, the Twitter account for Sci-Hub tweeted a screenshot of an alleged email from Cloudflare, the content delivery network provider for Sci-Hub (which acts as an intermediary between the user and website host), informing Sci-Hub that its service would be terminated in 24 hours. At the time of writing, the main Sci-Hub domain is inaccessible on the web, but the mirror sites mentioned in the screenshotted email from Cloudflare are still active.

Cloudflare’s termination of service is due to a court injunction against Sci-Hub, a Cloudflare spokesperson told me over the phone. That order was handed down by a federal judge in November when the American Chemical Society, another academic publisher, won $4.8 million in damages against Sci-Hub. The decision also included an injunction requiring search engines and internet service providers to block Sci-Hub, a digital blockade unusual for the US.

“In these circumstances, we look at the court’s order and make a determination whether or not we think it applies to us,” the Cloudflare spokesperson told me over the phone. Cloudflare was not specifically named in the order against Sci-Hub initially, but when the judge denied the Computer and Communications Industry Association’s (CCIA) amicus brief asking that search engine blocking be removed from the order, the decision named Cloudflare’s specific services.

“The impact of us taking down our services would be to impact the entire [Sci-Hub] website,” the Cloudflare spokesperson said.

Motherboard attempted to reach Elbakyan through an email address on her website, engineuring, and through Sci-Hub’s Twitter account, neither of which were immediately answered.

It’s unclear if Cloudflare terminating Sci-Hub’s service will have a significant or long-lasting effect on the platform. On February 3, the Sci-Hub tweet accompanying the Cloudflare email said that “[It] is not critical, but may cause a short pause in operation.” Even without an official website, Sci-Hub has a Tor version that circumvents blocking by internet providers. Users can also access the service through Telegram, a messaging app.

In previous interviews, Elbakyan has said she believes that Sci-Hub is important because scientific knowledge should be free for all. “Research articles are used for communication in science,” she wrote in a 2016 email interview with Vox, “but the word ‘communication’ implies common ownership by itself.” The site started as a script that Elbakyan developed to automate her process of pirating paywalled papers. She released the script to members of a molecular biology online forum in 2011, and since then it has grown tremendously. Sci-Hub is now a resource to download 64.5 million academic papers and it’s estimated to hold more than two thirds of the world’s major contemporary research—all for free.

Her model has experienced a great deal of backlash. In June 2017, for example, academic publisher Elsevier won a $15 million lawsuit against Sci-Hub. But Elbakyan didn’t have the money to pay damages even if she’d wanted to, she told Torrentfreak at the time. The lawsuit also resulted in an order for Sci-Hub’s operators to cease their activities. However, as Elbakyan does not live in the US and has no US assets, it did little to halt Sci-Hub’s activities, instead drawing attention to the site and increasing Sci-Hub’s downloads.

Still, Sci-Hub is resilient, popping up in a domain name whack-a-mole, and their founder is thought to be in hiding, though the US discovered that the site’s servers were based in Russia after a 2015 injunction by Elsevier. Elbakyan said in the 2016 Vox interview that it is not possible to shut down the website completely, but “it is possible to force it into the dark corners of the internet.”