i sit here watching nostr events in my logs all the time and i use it over a vpn at best the packets are tagged with my VPN address and the relays themselves don't keep this information... i am trying to stop an incessant broadcast from some nutter who republishes the first nostr event over and over from like 10 different VPNs
my relay isn't seeing the origin address, only the VPN tunnel side is
but people who are not using vpns are indeed telling the relay's server where they are... the reverse proxy could be modified to log this information and pull the pubkeys out of the events easily