In theory, the airport device could provide backup from its facial image of a passenger to all that is known about the person that is held on other government software. This information can range from a driving license to a criminal conviction.

But the airport machines have developed a serious glitch, and some of the results have been startling.

An MI5 leaked memo to the Home Office, in charge of all British airport security, claimed the face scanners installed at Manchester airport revealed that the actress Winona Ryder showed a 52 percent likeness to Osama bin Laden in terms of the facial characteristics the machine was programmed to select.