Able Danger Blog


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Saturday, March 11, 2006

Network Theory and Able Danger

From the New York Times:

After Sept. 11, Valdis Krebs, a Cleveland consultant who produces social network "maps" for corporate and nonprofit clients, decided to map the hijackers. He started with two of the plotters, Khalid al-Midhar and Nawaf Alhazmi, and, using press accounts, produced a chart of the interconnections — shared addresses, telephone numbers, even frequent-flier numbers — within the group. All of the 19 hijackers were tied to one another by just a few links, and a disproportionate number of links converged on the leader, Mohamed Atta. Shortly after posting his map online, Krebs was invited to Washington to brief intelligence contractors.

Announced in 2002, Adm. John Poindexter's controversial Total Information Awareness program was an early effort to mine large volumes of data for hidden connections. But even before 9/11, an Army project called Able Danger sought to map Al Qaeda by "identifying linkages and patterns in large volumes of data," and may have succeeded in identifying Atta as a suspect. As if to underline the project's social-network principles, Able Danger analysts called it "the Kevin Bacon game."


Of course, the author goes on to dismiss Able Danger's importance without even looking at the program in any depth, but I guess at least they mentioned it:

Able Danger analysts produced link charts identifying suspected Qaeda figures, but some charts were 20 feet long and covered in small print. If Atta's name was on one of those network maps, it could just as easily illustrate their ineffectiveness as it could their value, because nobody pursued him at the time.

One way to make sense of these volumes of information is to look for network hubs. When Barabasi mapped the Internet, he found that sites like Google and Yahoo operate as hubs — much like an airline hub at Newark or O'Hare — maintaining exponentially more links than the average. The question is how to identify the hubs in an endless flow of records and intercepted communications. Scientists are using algorithms that can determine the "role structure" within a network: what are the logistical and hierarchical relationships, who are the hubs?


Identifying these hubs is exactly what Able Danger did. They identified five hubs, or cells. One in Brooklyn, one in Hamburg, one in Malaysia, one in Yemen, and one in either Kenya or Mauritania depending who you ask. In addition to using computer models, they also used experienced analysts to make sense of the data and weed out the irrelevant links. In other words, the problems the author is trying to solve, are the ones Able Danger was able to work around. The chart Atta was on listed forty to eighty terrorist organized into five cells. You can't get much more specific than that, even if people want to keep dismissing it as insignificant.