Social media site Reddit has banned two of the largest far-right “subreddits” groups it hosts, altright and alternativeright.

The subreddits have been used in the organisation of America’s resurgent neofascist movement but the final straw for Reddit was the two groups’ participation in what is known as “doxing”: sharing private personal information without permission as a form of online harassment.

The subreddits were specifically banned for breaking Reddit’s content policy, according to a message posted by the site admins, “specifically, the proliferation of personal and confidential information”.

In a statement, Reddit said it aims to be a “welcoming, open platform all by trusting our users to maintain an environment that cultivates genuine conversation and adheres to our content policy.

“We are very clear in our site terms of service that posting of personal information can get users banned from Reddit and we ask our communities not to post content that harasses or invites harassment. We have banned r/altright due to repeated violations of the terms of our content policy. There is no single solution to these issues and we are actively engaging with the Reddit community to improve everyone’s experience.”

Reddit did not make it explicit which content infringed its rules, but it is believed to be attempts to dox the protestor who punched a white nationalist during a TV interview at Donald Trump’s inauguration.

Speaking to the Daily Beast, one Reddit moderator claimed that the ban was instead a result of its “record monthly traffic” (Reddit moderators, like the creators of individual subreddits, are all volunteers with no official relationship to the site’s staff). “It’s clear that Reddit banned us because we were becoming very popular and spreading inconvenient truths about who’s ruining our country and robbing our children of a future,” the moderator said.

Doxing is one of Reddit’s few red lines when it comes to site-wide offences, alongside posting illegal content, inciting violence, or threatening, harassing or bullying people. It was banned on the site even before Reddit instituted rules banning sexually suggestive content featuring minors.