Terrorism False Positives
Security systems fail in two different ways. The first is the obvious one: they fail to detect, stop, catch, or whatever, the bad guys. The second is more common, and often more important: they wrongly detect, stop, catch, or whatever, an innocent person. This story is from the New Zealand Herald:
A New Zealand resident who sent $5000 to his ill uncle in India had the money frozen for nearly a month because his name matched that of several men on a terrorist watch list.
Because there are far more innocent people than guilty ones, this second type of error is far more common than the first type. Security is always a trade-off, and when you’re trading off positives and negatives, you have to look at these sorts of things.