Touchy Subject
And away from the main point of thread - but as long as we're there - the main perceived threat is presently from middle eastern organisations. It used to be from slavic countries (note I'm writing about the perceived threat) and from time to time from organisations in ireland, as far as UK has been concerned.
Now, with little to go on, any security man who ignored traits common to the countries of origin of the perceived threat, taken in combination with a sour "joke"as above would - politically correct or not, not be acting in the best interests of the traveller.
This is hard on the vast/vast majority of law abiding people from other countries and feeds the flames of hate but so does driving aeroplanes into 3000 odd unwilling human shields in a world trade center. Unfortunately it's war - quite true - "still they don't get it".