http://www.nytimes.com/2006/02/25/technology/25data.html?ex=1298523600&en=d231d2f98b31262a&ei=5088&partner=rssnyt&emc=rssPALO ALTO, Calif., Feb. 23 — A small group of National Security Agency officials slipped into Silicon Valley on one of the agency's periodic technology shopping expeditions this month.
On the wish list, according to several venture capitalists who met with the officials, were an array of technologies that underlie the fierce debate over the Bush administration's anti-terrorist eavesdropping program: computerized systems that reveal connections between seemingly innocuous and unrelated pieces of information.
<snip>
"The theory is that the automated tool that is conducting the search is not violating the law," said Mark D. Rasch, the former head of computer-crime investigations for the Justice Department and now the senior vice president of Solutionary, a computer security company. But "anytime a tool or a human is looking at the content of your communication, it invades your privacy."
<snip>
Ms. Knowlton began her investigation by importing telephone call records into her software and was immediately led to a pattern of calls between prisoners and a recent parolee. She overlaid the calling data with records of prisoners' financial accounts, and based on patterns that emerged, she began monitoring phone calls of particular inmates. That led her to coded messages being exchanged in the calls that revealed that seemingly innocuous wood blocks were being used to smuggle drugs into the prison.