A lot. Not sure how many. Hundreds. Lots of the porn communities for shit that I'm not interested in. Most of the vegan communities. Anime and furry porn, twinks and ladyboys, any women/girls with penises, bondage porn, any community that's just an endless stream of pissing and moaning, tankies and fascists, bimbos and anything that glorifies plastic in female bodies, anything to do with unhealthy bodies, proana, etc. some local communities where I don't live, a fucking baseball communities that posts 100 times a day and lots of team communities. Lots of communities on .ML
I browse all so that I see new communities as they emerge then block them if I'm not interested.