This has absolutly nothing to do with the fact they are Australian, its the fact they are human, and for some reason, many humans feel the need to hurt other humans for no particular reason.
This thread is starting to get a bit to close to being anti-australian, and its really not right, because you find this pathetic behaviour in every culture in the world, from the UK to Papa New Guinia to Alaska to Australia....keep the focus in the right place guys, because excatly this kind of '...australians do this blah blah...' kind of conversations where what triggerd this in the first place, except it woz '....eastern europeans blah blah...'