Yes, there are a few existing decentralized social networks but as far as I know, they have not thought about or focused on some of the privacy-related issues that we want to highlight.
Shouldn't you at least mention once in your post that this is bit similar to diaspora? Or at least write a bit in there to say what your proposing does better than diaspora
The post was meant to be a concise description of an architecture, and is not meant to be comprehensive in any sense. I definitely agree that diaspora, and a few other projects out there feel like they should be a part of it and in fact, it started out as a more extensive post including a roundup, and a motivation on the state of social networks. Hopefully, it is the first of a few written works (as well as technical works) and there is plenty to be said about the topic.
How is giving Snapchat all of your geodata, detailed facial recognition data, etc. an improvement on privacy? Unless you're using a very specific and confused concept of privacy.
https://diasporafoundation.org/