To be consistant with this fencing and ASIC idea, I guess we will need to fence all bus stops, railway stations, ferry terminals... you name it... then require all citizins to wear their Oz card to gain access.
As has been demonstrated via the footy bombers, the terrorists themselves are not aviation focused as such. They wanted the maximun impact and apparently canvased many options with the hope to get thousands of casualitys. I find it hard to see how blowing up some 10 to 30 seat pax aircraft would even come into consideration.
If 10 to 30 victims was all that was required, then I am sure a public transport Bus would have been the target, with the added benifit that all Oz citys would be disrupted via bus checks and people fearing to travel.
This has already been proven to work.
Probably the bigest problem we now have with this fencing and ASIC thing, is it has now become a money makeing industry in itself, and the people who dreamed up the idea of fenceing bush airstrips probably dont want to admit it was a bad idea.