All this began during the war against terrorists in Iraq. Early on in the war on terror, the Department of Defense adopted many practices that major police departments take for granted. One of the more useful techniques is biometrics. That is, every time the troops encounter a "person of interest", they don't just take their name and address, they also use portable electronic tools to take fingerprints, a retinal scan and photos. All this is stored in a database, which eventually contained hundreds of thousands of records for Iraqis, Afghans, and other "persons of interest".

The fingerprints are particularly useful, because when they are stored electronically, you can search and find out immediately if the print you have just lifted from somewhere else, like off the fragment of a car bomb, is in there or not. The digital photos, from several angles, are also useful, because these pictures are run through software that creates a numeric "ID" that can be used by security cameras to look for some one specific, or for finding someone from a witness description. Other nations are digitizing their mug shots, and this enables these people to be quickly checked against those in the American database.

For decades, the U.S. military has regularly collected huge amounts of information from accidents, or even combat encounters. So now, it's no surprise that forensics teams examine each bombing (car or roadside) and combat scene, to see if they can get fingerprints. Often bomb makers are found this way, because raids frequently encounter suspicious characters, but no evidence that can lock them up. It only takes about two minutes per subject to take the biometric data, so any suspicious characters are added to the database. Now, after several years of this, raiding parties know to grab any guy who seems to panic at the sight of the biometrics equipment coming out. The terrorists know that biometrics is bad news for them, and they fear it.

Combat troops now get training on how to use the biometrics gear, and everyone now accepts that this stuff is a powerful weapon in the war against terrorists. Shifting this expertise to creating very difficult-to-fake Ids is not a large leap.