The company expanded the "ex parte temporary restraining order" so it could stage one-sided, sealed proceedings to take away rival businesses' domains, sometimes knocking thousands of legit servers offline.

Most famously, Microsoft used the power against No-IP, a company that provided dynamic DNS to thousands of customers, including a handful who were serving malware targeted at Microsoft operating systems. In a closed-door hearing that No-IP wasn't told about, Microsoft convinced a court to issue a sealed order No-IPs domains redirected to Microsoft's servers, on the grounds that the malware sites were "harming its brand."

Some of Microsoft's arguments to the court in the Waledac case were the same as they were in No-IP's case. They amount to this: Bad guys are violating our trademarks and harming the public, we need to stop this, give us control of the domains. Microsoft has made the argument successfully about a dozen times now, but there are some big differences between the No-IP case and previous cases. No-IP is a legitimate company whose services are used by thousands of law-abiding citizens. The fact that Microsoft could knock it offline, as if it were another Waledac, has many observers worried.

"The particular legal opinion that they were shopping for in the No-IP case was: if there is a a widely used resource on the internet that is not being well-tended to by its owner, then someone should be able to take it over," says Paul Vixie, one of the creators of the DNS system and the CEO at Farsight Security. "There's a long list of people who could take better care of Hotmail.com and Outlook.com than Microsoft does. I don't think they would want to live in the world that had that precedent."

Lawyers say that the tactic needlessly deprives companies like No-IP their right to be heard in court. Shortly after the No-IP takedown, the Electronic Frontier Foundation blasted Microsoft's actions. Eric Goldman, a law professor at Santa Clara University, doesn't like these ex parte temporary restraining orders either. "Our judicial system is designed to adjudicate disputes when adversarial litigants fight each other before an impartial decider," he says. "When that impartial decider hears only one side's story, and has no mechanism to hear anyone else's version of the story, our adjudicative process irreparably fails."