Since the September 11 terrorist attacks in New York and Washington, security experts in the United States are looking at new and improved types of electronic surveillance. These include face recognition systems and so-called computer vision. But the sophisticated electronic surveillance techniques pose practical problems, and they raise important questions about the rights of the people being watched.
British writer George Orwell predicted the constant gaze of "Big Brother" in his classic, futuristic novel "1984." Cameras - everywhere - recorded every person's every move. Now, the events of September 11th may hasten the development and use of technologies like computer vision.
Stephen Maybank, a computer vision researcher at the University of Reading in Britain, explained, "For very particular tasks, for fine detection of movement, then a human observer will do a lot better. But the human observer can't keep up that level of attention for 24 hours, seven days a week."
Unlike traditional surveillance cameras, computer vision would not simply capture and maintain images of people at airports or in stores. The system could have a database that compares an individual's movements to a "normal" range of movements programmed into the computer. So a person caught in the computer's eye moving too quickly - as if from a crime scene - could be marked as suspicious. Computer vision is not yet available on the market. But Mr. Maybank said he expects more sophisticated systems to come on line within the next few years.
Then there is face recognition technology now being installed at a number of airports around the United States. The only data that is stored are the images of suspected terrorists. The faces of everyone else filter through the camera's gaze.
"You know the first question before we introduce any new invasive technology into governmental use is 'will it make it safer? Does it in fact work?'," said Barry Steinhardt, associate director of the American Civil Liberties Union in New York. "Face recognition technology is simply [sophisticated enough] for the kinds of uses that have been proposed here."
For one thing, Mr. Steinhardt said, it is not going to work as a tool to identify potential terrorists at airports. "We don't have a photographic database of terrorists to match up to, so even if the technology was more reliable, there's nothing to do the match with," he said. "But beyond that, the technology is not terribly reliable. It has a high error rate. Both a high false positive rate and a false negative, meaning that the bad guys are going to get through and there are a lot of innocent people who are going to be fingered here as potential terrorists."
Advocates of the new electronic surveillance technology - such at the University of Reading's Stephen Maybank - admit it is more intrusive of peoples' privacy. "There will be a trade-off between the advantages and the disadvantages of these surveillance methods, and the exact point of trade off that one chooses must come out of discussion within society," said Mr. Maybank.
In one example, Robert Freeman of the Committee on Open Government with the state of New York says New York City police installed closed circuit cameras to monitor activity in Washington Square Park 24 hours a day. To Mr. Freeman's surprise, area residents liked the cameras. "Why? Because we feel safe bringing our kids to the park," said Mr. Freeman, "and the extent to which there is crime in an around the park has diminished." But several blocks away, crime increased.
Mr. Freeman said another problem is the creation of massive video databases that most Americans - by law - are allowed to see.