The subreddit, called r/altright was banned “due to repeated violations of the terms of our content policy,” according to the statement.

Alt-right is a term used to describe a strain of conservatism that includes white nationalists, Nazis, or other racist groups. It gained prominence during the recent presidential election after a number of alt-right adherents backed Donald Trump.

Reddit is home to free-wheeling and often controversial discussions about virtually every topic. Its terms of service seek to balance freedom of speech with some degree of civility, which is not easy to do. According to those terms, Reddit can ban users who post personal information about others, or harassing or hateful speech. Also forbidden is illegal content including “involuntary pornography” or content that encourages violence.

There is speculation that members of the subreddit posted personal information about the man who punched Richard Spencer, who coined the term “alt-right.”

Earlier Wednesday, the International Business Times reported that the number of Reddit’s alt-right subscribers grew 37% last month to just over 16,000 from 11,700. No sources were cited.

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Reddit closed the r/altright subreddit, two days after Reddit co-founder Alexis Ohanian posted an open-letter criticizing President Donald Trump’s travel ban involving seven majority-Muslim nations. The letter has generated upvotes, the equivalent of Facebook “likes.”

In response to his post, some Redditors, as Fortune reported earlier Wednesday, said Ohanian should back up his words about tolerance by shutting down neo-Nazi or other racist subreddits. Reddit has now done so in at least one case.

Asked whether other related subreddits were impacted, a spokesman said the closure related to r/altright only.

Date: (Feb. 1, 2017 8:08 p.m.) This story was updated to add more information about the reason for Reddit’s move.