Profiling has to come and it is not difficult and anyway Customs have used it for years. Anyone with an open mind, unafflicted by the deadening effect of political correctness and of average intelligence could walk along the line of the security queues and eliminate interest in a good 60% without much problem. Just practice on the next queue you see in an airport , railway station, Madam Tussauds,-or anywhere. With a little experience a further 20% could be added to the "go straight through " list and even then there would be plenty more of zero interest. Resources spent on 20% rather than 100% would have a much better chance of discovering anything that shouldnt be there, whatever form it comes in.