Racial profiling upsets the moderate majority from whom we get intelligence, resulting in more recruits for the extremists and less useful information for us. AFAIK we cracked the latest bomb plot precisely because we tried to accommodate the moderate majority and they in turn warned us of suspicious individuals. Doing it secretly doesn't help either, as word will out, most will be upset that you're doing such profiling, and the remainder will be upset you're trying to fool them.

Insaneapache, I live in the city that was bombed last year, regularly going through the stations that were bombed last year. I admit I get a little tentative when travelling by train or tube and there are dark-skinned people carrying bags nearby. But then I remind myself, I am British, I will not let this get to me, I will live as I have always lived, terrorist or no terrorist, and I at least put on the appearance of behaving normally. There are old ladies around who lived through the blitz, who regard this as nothing more than a nuisance, who am I to worry myself to death over this?