What ever happened to privacy? The simple right to be left alone? Surveillance cameras track our movements. Governments monitor our phone calls, e-mails, and Internet habits. Insurance companies know what drugs we take. Banks and credit agencies keep tabs on our smallest purchases. And new technologies--which gather, store, and share information as never before--have made all of this possible.

But, as the acclaimed social thinker Wolfgang Sofsky shows in this brief and powerful defense of privacy, neither technology nor fears of terrorism deserve all the blame. Rather, through...