"Thought experiment"? Doesn't this post describe Diaspora?

https://diasporafoundation.org/

Or StatsuNet/GNU Social.

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.

In talking to millenials, I've discovered (sadly) that they don't care much about privacy. They draw the line at revenge porn.

They do care about privacy - which is why so many people use snapchat instead of posting to their facebook walls

Well, privacy in the sense that they don't want their mommies and daddies see what they post.

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.

It's "privacy" in the sense that it's nominally shielded from people you don't explicitly message, not Snapchat itself or nation-state actors.

Not that it really shields from anyone, since people regularly take screenshots of Snapchats and share them.

This reads like a parody, or an "I'm the ideas guy" joke.