Communications of the ACM

A private overlay may ease concerns over surveillance tools supported by cellular networks.

CACM Administrator

The following letter was published in the Letters to the Editor of the September 2011 CACM (http://cacm.acm.org/magazines/2011/9/122792).
--CACM Administrator

Besides being a great article on its subject, Stephen B. Wicker's "Cellular Telephony and the Question of Privacy" (July 2011) also identified a game-changing direction in privacy. Consider that the word "privacy" is oxymoronic when discussing radio transmission; by definition, a radio sends our stuff to places totally beyond our control or authority; think postcard rather than envelope. We can't give away something and still claim to own it and presume we can tell everyone else how to use it. To my knowledge, no legal precedent exists to empower a nail maker to decree all builders use its products only pointy-side down.

This is a trend (and fallacy) sanctified by the software industry (and others), claiming "It's mine, even when we have it." Absurd, of course, though it seems to function as the basis for everything from copyright law to digital privacy.

Utterances overheard at a distance are not private; neither are postcards, signs in the front yard, or a radio or wire-line signal. A government might wish to guarantee a certain right of privacy for some particular technology, except that such a guarantee would be a matter of contract law, not of practical expedience. The postal service guarantees privacy (within limits) as part of its service. The phone company does not. I know of no service that allows remote talking that also guarantees confidentiality. The guarantee is to try to ensure confidentiality, or good faith.

Our expectation of privacy ends when the communication leaves our point of control, save for specific guarantees from the final authority, in the U.S., the Federal Government.

What Wicker called "context information" cannot be made private by definition (or the service stops). Presuming protection of related content is just silly; A gives it to B, and B may now do whatever it wants with it or whatever it thinks it can get away with. Wrangling legalisms about what is permitted is the equivalent of rearranging deck chairs as the ship of privacy heads for the bottom.

David Byrd
Arlington, VA