Here is an interesting piece from Wired. Bruce Schneier, Security Matters, Wired, 26 March 2009.
The piece talks about the challenges of maintaining privacy and a "Katz" level of privacy in an increasingly wired society.
matters because it's the constitutional test, based on the Fourth
Amendment, that governs when and how the government can invade your
Based on the 1967 Katz v. United States [389 U.S. 347 (1967)] Supreme
Court decision, this test actually has two parts. First, the
government's action can't contravene an individual's subjective
expectation of privacy; and second, that expectation of privacy must be
one that society in general recognizes as reasonable. That second part
isn't based on anything like polling data; it is more of a normative
idea of what level of privacy people should be allowed to expect, given
the competing importance of personal privacy on one hand and the
government's interest in public safety on the other.
The problem is, in today's information society, that definition test will rapidly leave us with no privacy at all.