I'd imagine it depends on the client you're using. You're much better off just curating your own mute/block list because even if anything was done, said individual could just spin up a new npub.

That said, all I can say is don't ever go on the global feed. There is porn galore. I've quit checking it myself.

Web of trust is crucial for a nostr experience just like in the real world:

You mostly just interact with people above a certain trust threshold.

This relies on your follows in nostr, and the app you use.

The app needs to implement this stuff properly and heavily rely on user choice, balancing direct user preference with discovery of potential good stuff that the user might like.

In any case, showing everything is a mistake in any context in my opinion. Example: only show posts from a users follows but then show *all* replies in the thread. Bad user experience.

Your question about reports: interpretation depends on the app you are using but most apps add these ppl to your mute list which will hide any content from that particular user. But whitelisting by your follow network (and some algorithmic extension of that) is better than blacklisting.

Also, communities are becoming better entry points to nostr than "twitter-like" apps. It is much more relevant and there are less surprises like your case.

Chachi.chat , flotilla.social and oxchat.com are good examples where you can join or create moderates nostr communities tied closely to a single relay.

Ive seen some dreadful stuff on here and I guess its one of the downsides of this nostr protocol. We need tools to better deal with it.