To no one's surprise, many terrorists aren't willing to divulge their identities -- they'd rather cover themselves head-to-toe than risk a drone strike or police bust. Researchers, however, may have made it that much harder for these extremists to hide. They've developed a biometric identification technique that can pinpoint people by the V-for-victory hand signs they make. By measuring finger points, the gap between them and two palm points, scientists can identify someone even when there are no other telltale cues. In some cases, it was more than 90 percent accurate.