Broad screening at airports does make travellers safer. As Bruce Schneier, a security technologist, argues: "As counterintuitive as it may seem, we’re all more secure when we randomly select people for secondary screening — even if it means occasionally screening wheelchair-bound grandmothers and innocent looking children." [1] This is because otherwise terrorists can observe what profiles our security forces are using, by seeing who is stopped and checked more closely, and thus adapt themselves to not be caught by them. It is not beyond the realm of possibility that al-Qaeda could recruit children or the elderly to be its suicide bombers, and hence random checks are essential in order to allow us to have some chance of catching these terrorists,. If we simply resort to profiling, we will always be one step behind the terrorists and will have no chance of catching any of their operatives who fall outside the profiles.  [1] Schneier, Bruce. "Profiling Makes Us Less Safe". New York Times, Room for Debate. 4 January 2010.