Mr Turnbull has announced on  information provided to him by the police and the security services that home-grown Australian terrorists had hatched a plan to smuggle a meat mincer aboard a domestic flight with intent to kill the passengers and crew by poison and crashing the plane. A graduate from a sheltered workshop for the criminally insane would hardly seek to take on board a metal meat mincer as a device to dispense lethal gas.  But when you set up a high powered department for homeland security, you create a demand. This is the response. These dickhead arrestees will walk.