Pretty sure there are like 10 people in Mississippi that use Nostr so this is a moot point. But it's not so simple.

Let's pretend [insert name of big Nostr client] is found to be facilitating this kind of access at scale for children in Mississippi then the owners that client's legal entity (lets say it's in Europe somewhere) could be issued active arrest warrants for a felony, and this would likely be flagged by US federal authorities and could result in these individuals being denied entry into the US.

And people tend to like being able to visit the US.

Also Google and Apple would also remove the app from their stores in response to the felony charges.

And if this happened then all other large Nostr clients and Nostr media hosts that are run by people who either enjoy visiting the US from time to time or who actually live in the US would take note and (likely) make some adjustments vis a vis how they connect to relays.

And the same sort of thing for the operators of larger relays. The law clearly states that it doesn't matter where in the world you are or what you are operating (relay, client, etc.) if you're not doing your best to prevent access by children in Mississippi you as the operator can be issued an arrest warrant by the State of Mississippi and goodbye worry-free future trips to Disney World.

Works like that.