I'm interested in protecting people who know each other in real life, and giving them a local telephone access method of communicating by BBS posting from random locations within a local area code (city) with telephone jacks. And also allowing for local public discourse on a local telephone BBS. I don't want to or need to talk to someone from a foreign country about domestic politics, or about cooking recipes, or what good restaurants there are in the city to visit.

The goal isn't to protect the location of the telephone BBS server, but to allow for local client users to access the BBS server quickly, encrypted, anonymously (no login identity), possibly with a universal password for users of the service (darknet), with access only from local area code numbers from anywhere in the city.

The clients gain anonymity ( aside from stylometric issues) from posting from telephone jacks that are not connected to their residential or employment locations. And by cycling locations around the city and possibly not reusing the same locations more than once or twice in a year. Pseudo anonymity will be gained by using a code word / call sign / pseudonym and posting pgp /gpg encrypted messages in threads dedicated to encrypted messaging, Post for Coolcat235 : qPgTnOxWiUIL+PFl4NFnUWLWM5ZVzX4oziQJEsxgodaigol908HXTvHS2MZzS/QevFq9BGmxFPQQ and so on. The users that know each other in real life can pre-share a signed symmetric Key (AES) , or sign each other's RSA keys for use with gnu privacy guard.