[ezst]

I'm saying that if Service B is under a jurisdiction that has export control regulations (i.e. all of them) and somehow decides that "users from country X are non grata" ; or under a jurisdiction that oppresses on the basis of your political beliefs, skin color, sexual preference… (both of which characterise the current Trump administration, under which Signal operates) then the service operator has no choice but to lock you out of your account, making the whole cypher/crypto argument moot.