It's an interesting question you've raised in your last para,...

It's an interesting question you've raised in your last para, about a government having no right to stop citizens travelling from or entering Australia. It probably should be in a separate thread as it's more about constitutional law than WEB. It is the very question being tested soon in the High Court (an application was lodged today).

There is no explicit law allowing or preventing the federal government from banning international travel, and none that prevents them from imposing a ban on returning. That's why the current regulation is being tested. The question goes to the heart of the implied right of Australian citizens to leave, enter and travel in their own country, and whether the Minister for Health is acting within his powers or going beyond them. But it is an implied right. Similar to the implied right of freedom of speech. There is no "right", no law that guarantees freedom of speech – and plenty that restrict it. We just like to think of it that way, and same for travelling. Hence the High Court is being asked to make a ruling about what the Constitution meant by certain powers given to the federal government.

The States have a right to prevent travel under their own constitutions – hence the border closures. These seem to be accepted as necessary under the circumstances. But the idea of locking Australians out of the country – especially when facing such a grave threat – just feels wrong. Like the line in The Castle: it's just the vibe.