I imagine some would be moderated by their founders, and others might adopt conventions where their members moderate. Moderation in such server-oblivious syste

I imagine some would be moderated by their founders, and others might adopt conventions where their members moderate. Moderation in such server-oblivious systems would chiefly be a label applied: "this conforms to our norms" or "this doesn't conform". Being a member-in-good-standing of a community would be a standing default that one's messaging is presumed conformant. Violations beyond the tolerance of the community would flip that "presumed conformant" bit to "presumed in violation", so that software wanting to show the community-conformant view knows what to do. (This only requires cryptographic identities & messaging, not centralized server sysops with delete privileges.)