Fine but only after they stab somebody?
Should be a no-brainer, whether in Australia or here in the U.S. Anyone who attacks fellow citizens of their own country because they wish to destroy that country is the very definition of a traitor, and should not only lose their citizenship but be executed.
One of those clauses that makes little sense upon examination. They created the problem and it's theirs, not the country they betrayed. Australia owes them nothing. To say otherwise is like saying you owe cancer cells a new liveable situation when you drive them out of your body with chemo.
‘home-grown’ is a misnomer.