The Christian Science Monitor reports that the US government is secretly developing a surveillance system called Analysis, Dissemination, Visualization, Insight, and Semantic Enhancement (ADVISE):

The US government is developing a massive computer system that can collect huge amounts of data and, by linking far-flung information from blogs and e-mail to government records and intelligence reports, search for patterns of terrorist activity.

The article has a side-bar that, according to US Government auditors, says SecureFlight held records on 43,000 people not accused of terrorism. This points directly at the very real threat of data-mining being used for nefarious non-security related purposes.

ADVISE is apparently meant to stitch together a vast array of data points in order to more accurately understand behavior and avoid false positives. However, an analytics expert from IBM had this to say about the current capabilities of such a system:

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.”