Still some of those, as with any social media platform. I have come across a few objectionable things, I just blocked and moved on. But you pick who you follow so you pick who shows up in your feeds. Each relay has their own moderation policies, so (like Lemmy), you can pick relays which suit your moderation preferences (which effect the "trending notes"/public square section). Most nostr apps by default upon install will ask you if you want to automatically filter out crypto/nsfw/foul language/etc. I picked at random and didn't enable many of the filters.