We are in an area of law and legal application that is getting close to the substance of free society. Value judgments can go this way or that. And where you start forbidding citizens their freedom of movement, you need very important trade-offs to justify it and the hardest of proof for government to act. Otherwise you might find yourself in a tight spot a little later. This was the discussion in the 1920s, when fascism was the rage. And I think it wiser to err on the side of maintained freedom at a reasonable risk than risk freedom. But it is by far and away not clear cut.