Whatever is the lowest barrier to entry, initially. Survey your neighbors’ preferences and go with the majority. Once you gain critical mass, you can introduce secure comms, mesh network etc. Well, that’s one theory. Another theory is that if you have some onboarding friction, you will weed out a certain class of neighbors.
I like Signal and use it daily, but it can give people a false sense of security. Most media are vulnerable to social engineering attacks, including Signal. What good is end-to-end encryption if a bad guy gets access to your unlocked device?
“”What good is end-to-end encryption if a bad guy gets access to your unlocked device?””
It is Neighborhood Watch, what kind of secret information would be on someone’s phone that would be serious?