Where does this end ? If twitter is not a public square but a megaphone, then a public square is also not a public square but a megaphone, technically speaking

Where does this end ? If twitter is not a public square but a megaphone, then a public square is also not a public square but a megaphone, technically speaking I (possibly with the support of a mob) can ban you from entering the public square and you can still stand on the roof of a nearby house and shout your ideas. Your internet connection is also not a public square but a megaphone, your electricity is not a public square but a megaphone, and your mobile connection is not a public square but a megaphone. I can lobby gas station companies to never service you and that wouldn't be harrasment, you just need to find another gas station not controlled by all the ones I lobbied, or possibly start one of your own :). Anything that is afforded to the public (for whatever price) is a public square, any ban or deprivation from it amounts to censorship and exclusion. This is unremarkable on the micro scale (e.g. a golf club or a coffeshop) because alternatives are plenty and easy to find, but when a huge corporation with effectively monopolistic control of a huge slice of some market does it it's worrying. And it should worry you even if you happen to like the effects of one particular incident, because the same machinery that allows such incidents to happen is bound to impact you someday.