You know, I can recall, that at certain times in the past when things were at their worst with the IRA, people in London would sometimes react a bit strange the minute someone with an Irish accent spoke (no matter how innocent).
I guess the same is happening here, with each person having an image (rightly or wrongly) in their mind of what a plane bomber looks like. If profiling has been shown to work, with the likes of El Al,then I see no reason not to adopt it. The threat won't always be the same, and profiling is a technique which seems very flexible.