Kashmir Hill, John Ismay, Christopher F. Schuetze and Kashmir Hill writes about technology and privacy.The device — a relic of the vast biometric collection system the Pentagon built in the years after the Sept. 11, 2001, attacks — is a physical reminder that although the United States has moved on from the wars in Afghanistan and Iraq, the tools built to fight them and the information they held live on in ways unintended by their creators.The biometric data on the SEEK II was collected at detainment facilities, on patrols, during screenings of local hires and after the explosion of an improvised bomb.Mr. Marx used the SEEK II on himself; when he turned it off, a message popped up, asking to connect to a U.S. Special Operations Command server to upload the new “collected biometrics.” Over the past year, Mr. Marx and a small group of researchers at the Chaos Computer Club, a European hacker association, bought six biometric capture devices on eBay, most for less than 200 euros, planning to analyze them to find any vulnerabilities or design flaws.“They didn’t care about the risk, or they ignored the risk.” Stewart Baker, a Washington lawyer and former national security official, said that biometric scanning was a valuable tool in war zones but that the collected data needed to be kept under control."