@ethanz If you like Mastodon, you’re going to poop bricks when you discover the work of Secure Scuttlebutt (https://staltz.com/an-off-grid-social-network.html) or my favorites, the Dat (https://docs.datproject.org/) and Beaker Browser (https://beakerbrowser.com/) projects!
Unlike federated, these offer real P2P (via distributed hash tables, like BitTorrent), cryptographically secure (also like BT), but with versioning, append-only logs, multi-writer capabilities &c. Would love to read about (or help with 🤓!) your research on these!