You can see the tweets and posts because a private company allows you to make an account, and even then you don't see all.

That's like walking into a Starbucks and reading the chalkboard. Everybody who can enter can read it.

Factual it's faster and easier to enter a Starbucks than creating an FB account.

And like we all know if FB decides to ban your account you can nothing do about it.

Doesn't sound like a public place to me