By integrating data you want into the visual field in front of you Google Glass is meant to break down the distinction between looking at the screen and looking at the world. When switched on, its microphones will hear what you hear, allowing Glass to, say, display on its screen the name of any song playing nearby…It could also contribute a lot to the company’s core business. Head-mounted screens would let people spend time online that would previously have been offline. They also fit with the company’s interest in developing “anticipatory search” technology—ways of delivering helpful information before users think to look for it. Glass will allow such services to work without the customer even having to reach for a phone, slipping them ever more seamlessly into the wearer’s life. A service called Google Now already scans a user’s online calendar, e-mail and browsing history as a way of providing information he has not yet thought to look for. How much more it could do if it saw through his eyes or knew whom he was talking to…

People may in time want to live on camera in ways like this, if they see advantages in doing so. But what of living on the cameras of others? “Creep shots”—furtive pictures of breasts and bottoms taken in public places—are a sleazy fact of modern life. The camera phone has joined the Chinese burn in the armamentarium of the school bully, and does far more lasting damage. As cameras connect more commonly, sometimes autonomously, to the internet, hackers have learned how to take control of them remotely, with an eye to mischief, voyeurism or blackmail.  More wearable cameras probably mean more possibilities for such abuse.

Face-recognition technology, which allows software to match portraits to people, could take things further. The technology is improving, and is already used as an unobtrusive, fairly accurate way of knowing who people are. Some schools, for example, use it to monitor attendance. It is also being built into photo-sharing sites: Facebook uses it to suggest the names with which a photo you upload might be tagged. Governments check whether faces are turning up on more than one driver’s licence per jurisdiction; police forces identify people seen near a crime scene. Documents released to the Electronic Frontier Foundation, a campaign group, show that in August 2012 the Federal Bureau of Investigation’s “Next Generation Identification” database contained almost 13m searchable images of about 7m subjects.

Face recognition is a technology, like that of drones, which could be a boon to all sorts of surveillance around the world, and may make mask-free demonstrations in repressive states a thing of the past. The potential for abuse by people other than governments is clear, too…In America, warrants to seize user data from Facebook often also request any stored photos in which the suspect has been tagged by friends (though the firm does not always comply). Warrants as broad as some of those from which the National Security Agency and others have benefited in the past could allow access to all stored photos taken in a particular place and time.

The people’s panopticon, Economist,  Nov. 16, 2013, at 27