it essentially means that only the permitted users can violate the privacy of their peers, the servers are programmed to restrict access without proof of membership in the group
Discussion
i'm done with fiat mining for today, wrote a nice paginated iterator thing for them
so now i'm back to realy, which i'm in the process of documenting fully
but after these thoughts, i am making a mental note that when i come to rewriting the documentation of #realy and its #geyser page i'm going to call it a "privacy protected" relay and define that concisely.
shifting the liability away from the provider is essential to enable providing service, any service that does not protect privacy in this way is instantly less marketable.