Social media based on the client/server architecture of the world wide web provides persistent data. Whenever posts are added to an archive or read from it, the data is always available, but the archive isn't owned by those who read and write the messages. It belongs to the owners of the server and they mine the data for information about their users. Wherever the central server is located, it will be halfway around the world for some user who is only sending a message to the other side of town. Problem are compounded if servers are based in a country with pervasive surveillance or even if messages only pass through such countries.

Peer-to-peer architectures, where everyone owns their own data and uses their own applications are close to the original conception of the world wide web. It was initially assumed that everyone who used a web browser would also run a web server. Instead, an electronic consumer society using web browsers to access an industry of web services has emerged. Peer-to-peer networks are overlaid on the internet so that peers can communicate with each other directly. The problem is data persistence. Unlike modern web servers, which are always on, consumer devices generally connect to the internet intermittently and data bandwidth is often metered. One solution is to use the peer to peer network itself as a distributed file system or a distributed database. Another solution is to use a hybrid architecture incorporating features of both client/server and peer-to-peer networks. A more radical solution is to dispense with data persistence.

Rather than attempt a comrehensive survey, I offer a representative sample of peer-to-peer networks. Both Beaker, which is based on the global Dat file system, and Patchwork, which is based on the global Scuttlebutt database, are part of large dynamic ecosystems that are evolving rapidly. Although only Tox currently runs on mobile devices as well as desktop computers, Andre Stalz is nearing completion of the mmmmm-mobile client for Scuttlebutt and Sarah Jamie Lewis will soon release Cwtch-IM, a mobile group chat app based on Ricochet.