>Where did I say that is how I think physical borders should be defended?

Where did I say you said that? Indeed, had you, I wouldn't have asked. But surely you see the similarities: Blocking non-domestic Internet stuff is imposing restrictions on what information/systems citizens are able to access, effectively curtailing the digital equivalent of a right to travel.

>In any case, even in a largely "free" country, I'm not entirely free to leave when and to where I might want.

What "free" country imposes routine restrictions on its citizens leaving? That you may be denied entry anywhere else is a related but separate issue.