U have a point though Captian Paranoia it wouldn't be hard for Bin Laden to use a nerve agent and cause a dent in the population of sydney. But i would expect the aussies to work extra hard at securing the city. When a country is in the whole world's eye they tend to pull out all the stops. Besides I'm sure the U.S. and U.K. are going to be giving a helping hand with security matters as well as every other country that will show up.