This is an interesting idea, although as an alternative analogy: in an apartment complex, you would go down to your mailbox and insert a key to authenticate you

This is an interesting idea, although as an alternative analogy: in an apartment complex, you would go down to your mailbox and insert a key to authenticate you to retrieve your mail. I think the biggest challenge to having on-premises software for all of this stuff is the maintenance of it - but a decentralized social media platform certainly sounds interesting.