I hate slipper slope arguments, but the march to tyranny is a very shallow slope of ice. Tomorrow it's "move 100 miles." Next year it's "pay $100 for the exit toll." In 2030 it's "we only allow 100 people to exit per day."
Right, this doesn't work in sovereign nations, only in federalism where there's a federal government that can guarantee some minimal set of freedoms to everyone (like the freedom to move to another state without impediment). Otherwise you just get the Berlin Wall.