This has been discussed/answered in other Nostr thread:

The links you shared talk only about spam. They do not talk about illegal content like CSAM.

There is no single approach as no central moderation exists. That's a feature.

So it's to relay operators in combination with WoT (web of trust) on the client (and sometimes relays)

	▲	peaseagee 6 days ago \| parent [-]
		So relay operators must also moderate everything that goes through their relay? How?