Anyone who was smart preserved their weapon off-site for this very eventuality.
Australia's semi-auto ban is often touted as a success by gun-banners here in the U.S. We're often told, "Australians love their guns and yet were willing to support common-sense bans on military-style assault rifles so why can't we?"
In truth, compliance in Australia was dismal. Officials conservatively estimated no less than 2.5 million firearms would fall under their ban. A mere 600,000 were turned in.