Physics theorizes the existence of wormholes that can transfer information point to point. But what physics theorizes is not the point.

Whether or not you could hypothetically construct a Faraday cage around the entire United States to limit international radio communications is not relevant, because it would be prohibitively expensive and blot out the sun.

What matters is what is feasible in practice, taking into account both the physical and economic realities. The internet exists and it will continue to exist as a result of both technical reality and economic necessity. The practical effect is the widespread availability of information teleportation.

Excluding information at the physical border but not over the internet is useless, but excluding it over the internet is both not happening now and infeasible to make happen, so excluding it at the physical border will remain useless and therefore has no justification.