I recently read an article about eight people having died in a medium German city last year because they walked over red traffic lights and have been hit by a car. They apparently had the feeling they had everything under control, but they underestimated the risk. The story reminded me about the daily business of information security people having to deal with risk perception of their managers and employees – luckily without casualty. But in a much more complex environment that is hard to oversee. False risk perception is typical for human beings. There are studies saying that the number of deaths of the 9/11 attacks was exceeded by the number of deaths caused by additional car accidents because people chose to drive instead of flying and driving is much more dangerous than flying.
As it seems there is also a false risk perception about terror attacks and the NSA spying. The NSA only contributed to the prevention of 4 out of 225 terror cases since 9/11 according to a study of the New America Foundation. The rest was prevented by the police etc. If there is only a small number of suicides because people are identified as terrorists by mistake because of misleading correlation results of the NSA, the spying would not only help to save lives, but even “kill” additional people. But I doubt there are public reports on the impact of such false positives.