Robert X. Cringley writes about CAPPS-II.
If you knew someone was going to release a biological weapon in a subway, what would you do? You can’t stop them. You know it is going to eventually happen. So how do you minimize the damage? Can you quickly evacuate the area? Can you thoroughly ventilate the area? Can you easily wash down and decontaminate the area? Many chemical plants have had these capabilities for 35 years. It is neither complicated nor expensive to anticipate a subway attack and minimize the amount of damage caused. But instead, we spend billions profiling terrorists.
We should spend less time chasing bad ideas based on unrealistic expectations and spend more time making it harder for terrorists to cause any real harm.