Investigating networks: the dark side.

A few months ago, Lawrence Wilkerson, a former U.S. State Department official and Army colonel, painted a nightmare scenario of how social network science can be applied in a battle zone. Describing how U.S. forces gathered intelligence to identify networks of insurgents after the 2003 invasion of Iraq, Wilkerson outlined something he called "the mosaic philosophy." The strategy, he claims, was similar to sequencing a genome. But instead of assembling millions of strands of DNA, investigators worked with data from interrogations of thousands of civilian prisoners. The general strategy of casting a wide net for intelligence gathering was familiar to all network researchers contacted by Science (see main text), but many expressed disbelief that it was carried out on such a grand scale in Iraq and Afghanistan.