Earlier quoted context omitted.
100% this. The 1st amendment protects free speech from the government. If you're in a bar, and they don't like what you're saying, they can ask you to leave. Then it all boils down to whether things like Twitter and Facebook are akin to the public square, a public street. That is hard to fathom given you are using their servers, their software, which they pay for and provide as a service (in something of a quid-pro-q…
But is Facebook like a bar? Or is it a pipe for user generated content?
IMHO, Facebook is like the bulletin board in a bar. A pipe would likely treat all content equally, Facebook does not do that, and I don't think there is an expectation that they would. If Facebook were a pipe, then there would be no recourse to moderate anything. Ergo it could be chock full of illegal content & porn, and if it were a pipe - nobody could complain to Facebook about the 'bad' stuff that is getting posted. Hence, seemingly they can moderate user-generated content pretty much however they please, it's their bulletin board. Further, if Facebook were a pipe, it could easily get flooded by several hundred/thousand payed trolls to post an overwhelming amount of content that Facebook could do nothing but allow to drown out everything else. Seemingly government telling Facebook they couldn't do (or how to do) moderation could put Facebook out of business (it could just wind up being crap/porn/spam)
I think the bulletin board analogy within a private space is likely a good analogy. The theme of the board is supposed to be posting for your friends by friends. I think it's within Facebooks right to then keep to that theme. The alternative is that they cannot in which case the users could utterly hijack the content within Facebook, and seemingly government regulation at that point would be preventing them from operating how they want (a seemingly very Ayn Rand like situation)