A. Michael Noll

(c) 2001 A. Michael Noll

All rights reserved.

September 2, 2001

[This material is based on an interview conducted on August 30, 2001 by the Daily Breeze in Torrance, CA.]


Video surveillance cameras are everywhere, watching and taping us. "Smile, you’re on camera." Hundreds of cameras capture every move at the Los Angeles International Airport, cameras catch every face at the toll booths of the George Washington Bridge, and cameras monitor the exteriors of most major buildings and many road intersections.

Some civil libertarians decry that all these cameras are an invasion of our privacy. The public authorities remind us of the criminals who have been caught and the lives protected. Many people feel more secure when they know that their safety is being monitored by a camera. In the end, it is a balance of public security with personal privacy.

The test that I suggest is whether a human observer or guard would be acceptable in the particular situation. If so, then there is no invasion of personal privacy. All the video cameras are doing then is replacing human guards in a much less intrusive manner and with the ability to record what is happening.

By my test, video cameras in the stalls of public toilets are not acceptable, since a human guard observing us "on the throne" would not be acceptable. However, a camera at the wash basins would be acceptable, since human attendants do indeed service rest rooms in some fancy establishments—and expect to be tipped too!

One question is whether anyone is at the other end watching the images being picked up by all the many cameras. Hundreds of cameras would require hundreds of eyes watching them. But the knowledge that the camera is there seems to be enough to deter much crime. The person monitoring the camera can become a "peeping-Tom," zooming in too closely to satisfy some urge. But a person walking up and peering too closely would be equally disturbing. Again, the previous test of privacy invasion would suffice to determine acceptability.

Many human guards wear uniforms so that their presence is strongly announced. But police in New York City are in plain clothes on many subway platforms. Many video cameras are easily recognizable, and some have flashing lights to make them even more recognizable and hence a deterrent to crime. But some cameras are hidden or disguised and hence comparable to plains-clothes police. Again, the test of acceptability is the human criterion.

It is all too easy to blame technology for invasions of privacy and to scare the public. But technology, wisely and appropriately used, can also protect both our security and our privacy.

Decades ago, I wrote a paper on the privacy issues raised by the information stored in computers and the need for assuring the security of that information. What I suggested was that a reasonable test for the security of the overall system was that humans¾not the computer¾should always be the weakest link and that audit trails could afford a level of security should a violation occur. In many ways, video cameras and recorders offer a form of "audit trail" should some problem occur. Most perpetuators of evil do not like to be recorded on camera committing their crimes.


Noll, A. Michael, "The Interactions of Computers and Privacy," Honeywell Computer Journal, Vol. 7, No. 3, (Fall 1973), pp. 163-172.