Let's consider that the question can be altered slightly to "how much private space can one single entity acquire?" Perhaps the current understanding of public/private is sufficient, e.g. "a private company can bar who it chooses, given that they do not violate some paradigm of protected classes, etc." The problem is that ONE entity owns a majority of a certain type of "space."

The redefinition would be to say, "once you own more than X% of something, it cannot be governed by existing rules about 'private' spaces?"

This is exactly the key in all conversations about banned accounts on private companies. In my opinion, either our habits regarding information intake using the internet needs to change, so that we use "the old commons" more often. (like real town squares)

Or there NEEDS to be a jurisdiction where if you are big enough, you can't just arbitrarily ban users from your space. The propagation of free thought and sound ideas depends on one of the points completely. There are huge problems, like how a company can be regulated when it is a global company. I don't want US law to facilitate Swedish spaces.

Honestly, the first idea where habits are formed back onto the "old commons" is probably the only real solution. But it's not exactly simple to change the habits of an entire planet.

That's one of the reasons that we need a blockchain-based microblog platform to take off and become popular.

First, it shouldn't be owned by a greedy prick or a a group of few greedy pricks!!