Reddit has shut down several Nazi and white supremacist subreddits after a policy change banning material that “encourages, glorifies, incites, or calls for violence or physical harm against an individual or a group of people.” The news was posted earlier today in Reddit’s moderator news forum, and commenters noted that at least 10 subreddits have been banned since then, including r/NationalSocialism, r/Nazi, and r/DylannRoofInnocent. Reddit is also banning anything that glorifies or encourages abuse of animals, including bestiality-themed subreddits.

This is a noteworthy shift for Reddit, which was reticent to ban almost any non-illegal material until 2015. It’s since removed some overtly hate-oriented boards over doxing and general nuisance, and “quarantined” others — including at least one of the newly banned ones, as Gizmodo writes — so they’re not visible to casual visitors.

It’s a theoretically broad rule, but Reddit seems focused on the site’s worst stuff

Reddit administrator landoflobsters, who posted this update, says that this is meant to clarify a previous ban on inciting violence. “We did this to alleviate user and moderator confusion about allowable content on the site. We also are making this update so that Reddit’s content policy better reflects our values as a company,” writes landoflobsters. “We understand that enforcing this policy may often require subjective judgment, so all of the usual caveats apply with regard to content that is newsworthy, artistic, educational, satirical, etc, as mentioned in the policy. Context is key.” CEO Steve Huffman will be taking questions on the site’s main announcements board next week.

Gizmodo notes that these were generally small communities, with user bases between 25 and 7,000 users. Several Redditors asked whether the site would ban notorious Donald Trump fan subreddit r/The_Donald — a possibility that seems unlikely, but may be addressed by Huffman.

Landoflobsters has answered at least a few questions from users about gray areas. Hunting-based subreddits should be fine, for instance — “we're mostly looking out for the really egregious examples of hurting an animal.” BDSM communities are also supposedly unaffected. Newsworthy and historical depictions of violence are all right, but one user expressed confusion about subreddits like r/JusticeServed, which currently has a front-page post called “Nerd puts bully on the ground in one punch.” (Nazi-punching memes could hypothetically be a similar edge case.) In theory, it’s a rule that seems broad and easy to misapply. In practice, its targets seem concentrated on the worst of the worst of Reddit — particularly Nazis.