Idk but I blocked like a dozen of them or so and they just disappeared. They have a few always-online users that you should just block when they pop up.

join an instance like sopuli.xyz that has defederated from them

As a stop gap, I've just blocked all their communities.

With sync for lemmy you can block instances by adding it to the instances filter.

No way yet, but it's supposed to be coming. In the mean time, if you block the major comms you'll probably remove about 90% of the hexbear posts from your feed.

Yeah, I have blocked hexbear & numerous weird gay/fetish porn communities. Make sure you're logged in. Click on the post & navigate to the community....then...towards the top before all the posts, there's a bunch of options. One being to 'block'. I have to scroll to find it.

Nav to offensive community

Block their ass

It should be noted I use Sync for Lemmy. You may or may not have this on your render/UI. Should be able to block.