At a time when we as a society can’t resolve issues about the privacy of data, issues that have been simmering for years, the emergence of facial recognition technology is very troubling. "Facial recognition blows up assumptions that we don't wear our identities on our person; it turns our faces into name tags," Ryan Calo, director of privacy at Stanford's Center for Internet and Society, told the San Francisco Chronicle.

The Constitution protects us from arbitrary arrests, and although police sometimes arbitrarily demand ID, that is only supposed to happen when there is probably cause. What then happens when a surveillance camera captures your face, and that "name tag" ties the image to your identity.

Picture demonstrators in Egypt. If government thugs can identify them by simply using a camera and a computer, would people feel safe protesting in Tahrir Square. Less alarming, but still annoying, is this: Marketers will have the potential to know what store you shop in even if you never take out a credit card; turning your face into the equivalent of a Web site's cookie...