No one is confused about the correct application of law, this is clearly an argument about principles as they apply to de-facto corporate controlled commons. Google is not the state, but essentially controls one of the few means of self publishing. It's not unlike company towns, and civil liberties. Just because it's not the state doesn't make it not an infringement.
I’d be interested in a citation for the proposition “social media is like a company town,” but I’m afraid if I promised to wait for one I might be here a while. The best I can do is direct you back to Marsh v. Alabama.
What makes it not an infringement is not that Facebook is not the state; it’s that Facebook does not encompass the traditional function of the municipality. The state action doctrine does not apply.
