Recent example from the banning of Bret Weinstein from Facebook: https://twitter.com/Liz_Shepherd/status/1319451084859953154?...
This is a Facebook communications person responding with an official reply to this incident. She describes herself as "Facebook comms, formerly @TheDemocrats and @SpeakerPelosi".
This is an example of power leakage. These institutions do in fact (i.e. de facto, not de jure) have elements of sovereign power given their relationship with the political/ruling class, it's just that they are not directly accountable in the same way that a government is. They engage in censorship for the benefit of the ruling/political class and use political formulae as a mask (TOS violations, "community standards" violations, exhortations to the first amendment, section 230 protections, etc) in the same way governments do.