A public square is a square of the public, not a private establishment. These are not public platforms, provided by the public for the public. They are private enterprises with a specific brand and desired code of conduct whose goal is to maximize engagement for profit. Essentially their existential risk is becoming a cesspool of toxic trolls and driving out the normals. This is the same, in the context of a public square being different than a private bar, which has an open door to the public but has discretion on who stays in the bar.

Example: You certainly can be kicked out of bars for being an asshole. Source: I’m an asshole.

That's not what "public square" means in US law. Private property is a public square if it is open to the public.

I think you mean public space:

https://definitions.uslegal.com/p/public-place/

Rather than public square:

https://nclplaw.org/area-of-law/rights-of-expression-in-the-...

Generally a public space doesn’t mean you can do anything you want in it, and the owner can restrict speech they deem offensive in their space and expel you. They can not block entry though without reasonable cause, and specifically not on protected statuses.

A public square is publicly managed space and the government can not restrict your speech on it but can restrict your conduct. The bar is very high for the government on a public space (although in practice the modern militarized police does what it pleases). They can also restrict the time and duration of your activity and speech if it’s somehow disruptive to the normal function of the space.

I would say social media is much more like a public space than a public square. It is not a sidewalk maintained by the public. It is not actually a public institution in any way whatsoever (publicly traded equity doesn’t make something a public entity).

As such, they can put up a “no shirt, no shoes, no racists, no service” and kick you out of their place of business.

> That's not what "public square" means in US law. Private property is a public square if it is open to the public.

“public square” isn't a term with a specific definition in US law, its a common-language term occasionally referenced in illustrating the logic of legal decisions, but not always with the same precise meaning.

Public forum is a term with specific legal meaning in First Amendment law, but it refers to a space used for official government business open to the public, not just a place open to the public. The latter is more like a public accomodation (but that is mostly relevant to anti-discrimination law.)

The "public square" is not a legal concept. Property and speech rights are. If we're discussing changes and nuances of law the general response should follow legal principles.

As to social media companies, they too have free speech rights. In the Supreme Court ruling Reno v. ACLU, the judges ruled unanimously that the Internet is a free speech zone, deserving of at least as much First Amendment protection as that afforded to books, newspapers and magazines. As such, your rights to post your beliefs ends exactly where another entity begins.