I had asked that question on another thread. to do this, they needed pools of hotel records, credit card records, immigration records, a bunch of other stuff to qualify a intersection of data down to a modestly short list of possible hits. where did they get it all from?
Improperly, I bet.
Might be related to nascent plans for Total Information Awareness
Very good question.
I recall Lt. Col. Shaffer saying something about two-and-half terabytes of databases. He mentioned the Internet and commercial pay databases. But I doubt that credit card usage can be had except from Visa, MC, AmEx, etc.
Of course, the pay databases may have records from tens of thousands of businesses and credit card purchases.
Check out this website, in which you will find the following...
The charts generated by these analytical techniques not only help establish relationships and focus the investigation, but they also have a hidden benefit – all the source information is documented on cards behind each link and entity on the chart, or through a direct link to the investigative database. This ensures that when the legal process begins all documentary evidence is organized and substantiates the charts.
http://www.i2inc.com/