Basically, you're looking for connections to already known groups of terrorists. If you find that terrorists X and Y communicate with each other, and that imme

Basically, you're looking for connections to already known groups of terrorists. If you find that terrorists X and Y communicate with each other, and that immediately after, X always calls Z, W, and Q, then you might want to engage in deeper surveillance of Z, W, and Q. If you find that Q always calls P, M, and N, and you also find that Y regularly calls N, that might suggest that N is somebody important within the terror network. This excellent article was on the HN front page a few days ago: http://kieranhealy.org/blog/archives/2013/06/09/using-metadata-to-find-paul-revere/ http://kieranhealy.org/blog/archives/2013/06/09/using-metada...