The Washington Post runs a good piece on the NSA wiretaps: Surveillance Net Yields Few Suspects, reporting that most of the wiretaps have led to dead ends -- and that many innocents are being tapped in the process. Although we still have few details of what the surveillance is, the Post discusses some of the datamining technology that sources suggest may be in use.
Jeff Jonas, now chief scientist at IBM Entity Analytics, invented a data-mining technology used widely in the private sector and by the government. He sympathizes, he said, with an analyst facing an unknown threat who gathers enormous volumes of data "and says, 'There must be a secret in there.' "
But pattern matching, he argued, will not find it. Techniques that "look at people's behavior to predict terrorist intent," he said, "are so far from reaching the level of accuracy that's necessary that I see them as nothing but civil liberty infringement engines."