Reddit is cracking down on the latest form of community protest: switching to Not Safe For Work (NSFW). Some subreddits had switched to NSFW to protest Reddit’s recent treatment of moderators and upcoming API pricing changes, but a Reddit admin — that is, an employee — said Wednesday that doing so is “inappropriate” and against the rules.

“Changing a previously SFW community to a NSFW community in order to protest Reddit policies is inappropriate for the members of your community and not acceptable overall,” the admin, ModCodeofConduct, wrote on Wednesday. ModCodeofConduct said that moderators may be violating Reddit policies by “incorrectly marking your community,” which can lead to warnings or removal.

Switching a community to NSFW changes things in a few ways: users have to confirm they are 18 years or older before they can view a subreddit, users must be logged in to the mobile app to access the community on a mobile device, and NSFW subreddits aren’t eligible for advertising — all restrictions that limit engagement and Reddit’s ability to make money.

Reddit’s crackdown on the NSFW switch seems to be working. On Tuesday, I had seen that r/formula1, r/HomeKit, and r/HomePod were all NSFW, but those subreddits no longer carry the label. A r/formula1 mod tells The Verge that the mods removed the NSFW label “after a series of terse threats from u/ModCodeOfConduct.”

According to that mod, ModCodeOfConduct sent this message:

While we can see you haven’t begun encouraging sexually explicit content from taking over the subreddit, we need to separate your community from the communities engaging in those behaviors so your community’s moderation team isn’t seen as complicit. Please correct the NSFW marking on your subreddit so that we can separate your community from those causing harm.

The r/formula1 mod is stepping down, citing “the admin handling of the API changes, the tone Huffman elected to use in every single interview, and because of the whole approach of u/ModCodeOfConduct.”

Another moderator, with both the r/HomeKit and r/HomePod communities, tells The Verge that they switched the subreddits back to SFW after “seeing the disciplinary actions (suspensions) taken against moderators of larger subreddits that were marked NSFW.” The mod noted that they had acted alone and not collaborated with the communities when making the decision to switch to NSFW.