Pmuzzy
take the point on religion - as how could you tell in the case of Irish terrorism that we suffered in this country who was Catholic of Protestant by looking at them.
I don't think anybody is suggesting profiling should simply be done by the guys carrying out searches in the airports (this being the last line of defence) Profiling can be based on many factors including the personal details provided by the passenger when they bought their ticket. In the case of Northern Ireland their address would probably be sufficient to indicate whether they are catholic or protestant, assuming the details provided were accurate of course, though depending on who's doing the profile such details can be verified.