Of course if they profiled passengers, they would most likely find that based on past history, demographics and behavioural science that a certain individual would emerge......but we can't be seen to discriminate can we?
That in essence is the problem. A friend of mine worked on a major airport security project for a global company, and their product was one which would have, based on algorhythms, thrown up potential murders/cowards/terrorists. Of course as PC swept the world it was decided it could not be implemented. So the MCTs won, and continue to win, as millions of air passengers daily are subjected to humiliating, pointless, time wasting 'security' procedures, which cost massive amounts of money.
Before PC swept the world ...... I was often picked out for questioning or a search. Male, travelling alone, booked at short notice, one way ticket, passport nationality A, issued in country B, resident in country C, journey beginning in country D and ending in country E. Passport full of stamps from 'odd' countries. Suspicious!
Did it worry me? No. Did it make me feel safer .... in some ways yes. Because I understood that the people were doing their job properly and with courtesy, not like the meatheads now who snatch water bottles out of children's hands, I was polite and cooperative. I remember leaving FRA with a huge box of Stollen and a bottle of German wine after one such stop, given to me by the 'interrogators' as thanks for being cooperative and making them laugh.
By the way, the Israelis still profile, and rightly so. And they don't seem to give a toss what the rest of the world thinks. Maybe others should adopt the same policy.