What's wrong with thinking of a "balance" between security and privacy

In this short essay inspired by a Orin Kerr's paper on an equilibrium-adjustment theory of the Fourth Amendment, Julian Sanchez raises some important problems with the traditional framing of security being "balanced" with privacy concerns:

In my own area of study, the familiar trope of "balancing privacy and security" is a source of constant frustration to privacy advocates, because while there are clearly sometimes tradeoffs between the two, it often seems that the zero-sum rhetoric of "balancing" leads people to view them as always in conflict. This is, I suspect, the source of much of the psychological appeal of "security theater": If we implicitly think of privacy and security as balanced on a scale, a loss of privacy is ipso facto a gain in security. It sounds silly when stated explicitly, but the power of frames is precisely that they shape our thinking without being stated explicitly.

There's a deeper problem, though: Embedded in the idea of the scales is a picture of a process for arriving at sound decisions–which if the metaphor is sufficiently pervasive we may come to think of as the only method for making sound decisions. A scale is a machine for reducing diverse objects–or in the metaphor, interests and values–to a single shared dimension. You might have items as varied as toasters and giraffes on the opposing plates of the scale, but all the scale cares about–or all we care about when we employ it–is that they both have weight and mass. Every other difference between the items in the balance is irrelevant so long as they have this one shared property, this one dimension along which they intersect, which allows us to quantify each in terms of the other.

The Trouble With "Balance" Metaphors

(via Schneier)

(Image: Balanced, a Creative Commons Attribution (2.0) image from ejmc's photostream)