A federal judge in Utah this week threw out a lawsuit by Koch Industries, a wealthy corporation that has opposed climate change legislation in the US congress, upholding the First Amendment right of anonymous activists to politically satirise the company online.

The individuals targeted by Koch, members of Youth for Climate Truth, last year issued a press release and posted a website impersonating the company and announcing that it had changed its position on climate change. Koch then successfully obtained a subpoena in Utah — home to the satirical site’s web hosting company — to learn the identities of the anonymous activists behind the parody. It then sought to sue them for trademark infringement, unfair competition, cybersquatting and computer hacking.

“The legal theories that they used were aimed at something else, something other than what was going on here,” said Deepak Gupta, the attorney who represented the activists pro bono through the public interest group Public Citizen. “Trademark infringement is about commercial speech where someone is using the mark of somebody else in order to pass off goods and services. That’s just not what was going on here. The only competition here was in the marketplace of ideas, not in the marketplace of goods and services.”

The federal judge dismissed those claims and barred Koch from releasing the identities of the activists obtained in the subpoena Gupta said never should have been granted in the first place.

“Imagine that we hadn’t agreed to represent our clients and come into the case,” Gupta said. “[Koch] almost achieved what they wanted — they got a subpoena from the court to get the identifying information. And that has a huge chilling effect. If you can unmask anonymous critics, if people are intimated because of that, that has a huge chilling effect on speech.”

The case sets an important precedent as online satire becomes an increasingly popular tool for political speech. Activists last year impersonated BP on Twitter after the company’s disastrous oil spill in the Gulf of Mexico. The Yes Men also famously pulled off a similar stunt in Washington in 2009 impersonating the US Chamber of Commerce. It issued a press release and held a live — and very convincing – press conference announcing that the conservative business organisation had finally seen the light on climate change. A law suit by the Chamber is currently pending in DC.

“The most immediate effect of the Utah decision is that it’s going to be persuasive precedent in DC,” Gupta said. “That shows this isn’t a one-off [case] by any means.”