'Western Brown or fierce snake' + 'attacks without provocation' I think you need to check your facts mate!!!

even Wikipedia could help you with some basic facts like distribution and temperament of the snake you are talking about....

http://en.wikipedia.org/wiki/Inland_Taipan

for a snake collector you dont seem to know much about them???!!!

As for snakes in a houseyard, especially given the difficulties in accurately identifying Aust elapid snakes, I reckon you have a good case to kill them and this is backed-up by law. Of course there are safety issues involved where the human can easily become the victim!!