A subscription-only article in the Economist argues that broad surveillance (face-scanning systems that are in fact almost useless at spotting terrorists, or widespread wire-tapping and interception of Internet communications) is generally the sign of a badly designed system of security. The failure to predict the September 11th attacks was one of data sharing and interpretation, not data collection. Too much eavesdropping might actually exacerbate the problem, because there would be more data to sift. It would be better to step up intelligence gathering by humans.