The government should not be building predictive data-mining programs systems that attempt to figure out who among millions is a terrorist, a privacy and terrorism commission funded by Homeland Security reported Tuesday. The commission found that the technology would not work and the inevitable mistakes would be un-American.

The committee, created by the National Research Council in 2005, also expressed doubts about the effectiveness of technology designed to decide from afar whether a person had terrorist intents, saying false positives could quickly lead to privacy invasions.

The report validates ACLU fears that the practice of data mining is not only vastly invasive to Americans’ privacy but is also ineffective.

“Data mining as preventative law enforcement is alchemy at its worst,” said Caroline Fredrickson, director of the ACLU Washington Legislative Office. “Given the administration’s steady creep towards a total surveillance society, this report could not be more relevant. It is a scathing rebuke of the Bush administration’s policy of vast and indiscriminate information gathering. A major pillar of the administration's post-9/11 policy has proven itself, as we said it would, to be wholly unstable. The systematic and broad-scale surveillance of Americans is doing nothing to keep us safe. With data mining, it is clearer than ever that the risk far outweighs the reward.”

“This report validates the ACLU's longstanding claim that data mining for anti-terror and law enforcement work is worse than junk science, it is pseudo-science,” said Timothy D. Sparapani, ACLU Senior Legislative Counsel. “Government agencies that are spending billions on data mining to fight terror would spend their money more effectively trying to discover a magical formula to turn lead into gold. The bloated watch lists are a special case in point. Applying data mining techniques like ‘link analysis’ to the million-person watch list casts a stain of suspicion on everyone who encounters someone on that list – and will quickly balloon it to a hundred million-person watch list. If not stopped now, data mining will turn us all into suspects.”