Two men are going to fight this weekend, and HBO and Showtime have already thrown the first punch in the legal fight over online streaming of the match. Taking advantage of an increasingly abused loophole in copyright law, they have just won a court order requiring a host of third parties to block access to sites that may stream the fight. In other words, if you run a Wi-Fi network (for example, you’re a coffee shop) and someone may use your network to watch the Pacquiao/Mayweather fight via unauthorized sources, HBO and Showtime think they can force you to block your customers’ access.

HBO and Showtime are relying on part of the Copyright Act, 17 U.S.C. § 411(c), that allows a broadcaster to file a “pre-emptive” suit to stop planned infringing streams. As part of that lawsuit, a would-be copyright owner can ask for an injunction to prohibit the anticipated infringement. With respect to the Pacquiao/Mayweather fight, HBO and Showtime asked for, and got, a court order to prevent two websites from carrying out their purported plan to show the fight without authorization. In the lawsuit, they asked the court to issue an injunction against boxinghd.net, sportship.org, and those who are in “active concert or participation with them.”

But that’s not the worrisome bit. HBO also persuaded the Court to order “all service providers whose services will enable or facilitate Defendants’ anticipated infringement [] to suspend all services with respect to Defendants’ Infringing Websites, including all registrars, hosts, name servers, site acceleration providers, providers of video delivery resources, and providers of computer and network resources through which video transits.” In other words, any service provider who gets this court order has to “suspend all services” with respect to the enjoined websites—even though they never had a chance to weigh in.

You may not feel much sympathy for the websites in question. But this kind of site-blocking, without real legal process, is essentially one of the worst parts of the ill-conceived, long-dead Stop Online Piracy Act (SOPA) being brought in through the courtroom back door. HBO got an order to block content against those who act as intermediaries, even though they have nothing to do with the alleged illegality of the sites, are simply providing normal business services, and almost surely had no notice that they were about to be enjoined.

This is not the way our legal system is meant to work, and the good news is that it actually doesn’t. Federal Rules only allow courts to issue injunctions against those who truly are in “active concert or participation” with bad actors. We doubt that those who offer hosting services and video delivery, without more, can properly be considered in “active concert or participation” with the unauthorized streamers.

Imagine if a court ordered the TV news not to talk to people who allegedly planned to commit defamation, or ordered libraries to not lend books that hadn’t even been published, or told art supply stores they had to make sure no one could make infringing art with their materials. This is the basically same thing. HBO and Showtime may find it convenient to get a court to order unwitting intermediaries to block content, rather than going after people who might actually infringe their rights. But getting a court to edit the Internet, without due process, take us down a dangerous path that the Internet soundly rejected back when it was called SOPA. We’re keeping a close eye on this new trend, because whatever name it has, pre-emptive Internet censorship is bad news.