Relays not running over Tor have the ip addresses of users connecting. So most relays are logging the ip address of the nostr clients that write events. An logging for reading. Anyway, nostr not over tor is not private, it’s mostly signed unencrypted content.

With DM’s you’re exposing the sender and receiver, but not the content. There are proposals for private encrypted groups but they haven’t been finalized or implemented yet.

If we did have folks posting CSAM, and using known relays, the relay operator could get their ip address and hadn’t it over to the police with the content.