From Slashdot another story hinting at how government agencies are organizing to intercept and interpret Internet data. See FBI quietly forms secretive Net-surveillance unit.
My guess is that data mining large amounts of data produces so many false positives that organizations like the NSA and FBI have to set up large units to follow up on results. There is an interesting policy paper by Jeff Jonas and Jim Harper on Effective Counterterrorism and the Limited Role of Predictive Data Mining that argues that predictive mining isn’t worth it. The cost of false positives for industry when they use predictive data mining (predicting who might buy your product) is acceptable. The costs of false positives for counterterrorism are prohibitive as it takes trained agents away from better uses of their time. I doubt anyone in this climate it willing to give up on mining which is why The NSA is Building the Country’s Biggest Spy Center.
I wonder if we will ever know if money spent on voice and text mining is useful in counterintelligence? Perhaps the rumour of the possibility of it working is enough?