100% of the popular internet is a 'private square'. That's the problem.
There doesn't exist any platform right now where one can share an idea and have that idea go viral, unless the idea is first gated through private censorship.
Sure one could make their own blog or website to express their idea, but the chance of it spreading is then pretty much 0, because again any means for links or ideas to spread are all 'private squares' with their own censorship.
This is how the internet broke free speech. This is where the law needs to catch up with technology.