Worrals....
Although no single group claimed responsibility for the Hilton bombing it did achieve one aim of creating terror....plain and simple.
However,I agree that if a simpleton chooses to do something as is the topic of this thread then creating work for legal teams and then putting up with the cost of housing this person is too much...
As has been suggested simply blacklisting them from air travel in Australia for a set period of say 50 years with no refund for their money spent would probably be sufficient....
Perhaps also tattooing "I'm an idiot" on their forehead would also help.