[nobody_at_all]

How can an endpoint, no matter how large that endpoint is, be considered to be a common carrier?

Justice Thomas is hardly a reliable source for making it so.

[Turing_Machine]

How is Facebook any more an "endpoint" than AT&T?

[nobody_at_all]

Facebook is just an endpoint on the internet. Nothing more.

AT&T is an ISP among other carrier things.

How can a server, or a set of servers be anything more than an endpoint?

That you would compare ATT and FB shows a remarkable misunderstanding of the internet and WWW.