A content editor on Reddit’s science forum wrote Monday that the site has banned climate-change skeptics, and asks why more news outlets haven’t done the same.

“About a year ago, we moderators became increasingly stringent with deniers,” Reddit content editor Nathan Allen wrote in grist. “When a potentially controversial submission was posted, a warning would be issued stating the rules for comments (most importantly that your comment isn’t a conspiracy theory) and advising that further violations of the rules could result in the commenter being banned from the forum.”

Allen explains that climate change became an ironically heated topic among commenters on Reddit’s science forum, /r/science, which he described as “a window into the Ivory Tower” for “non-scientists” to connect with experts like himself.

Climate-change believers accused skeptics of being bought out by “big oil,” while the skeptics accused believers of being on the take from “big green.”

Despite the provocative comments on both sides described by Allen, and Reddit’s reputation as “passionately dedicated to free speech,” the self-described “PhD chemist” decided it was time for the skeptics to go.

“After some time interacting with the regular denier posters, it became clear that they could not or would not improve their demeanor,” Allen said. “As a scientist myself, it became clear to me that the contrarians were not capable of providing the science to support their ‘skepticism’ on climate change.”

As a result, about half a dozen content editors now practice “proactive moderation” on the science forum’s reported 4-million subscribers.

“As moderators responsible for what millions of people see, we felt that to allow a handful of commenters to so purposefully mislead our audience was simply immoral,” Allen said of the audience he previously described as “mainly academic.”

He later describes the same audience as “‘internet trolls’ looking to have a little fun upsetting people. Such users are practically the norm on Reddit.”

Allen then expressed surprise that removing an entire faction of commenters “resulted in a change in the culture within the comments. Where once there were personal insults and bitter accusations, there is now discussion of the relevant aspects of the research.”

“While we won’t claim /r/science is perfect, users seem happy with the changes made,” Allen said.

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