By Jay Stanley, senior policy analyst at the American Civil Liberties Union's Speech, Privacy and Technology Program. Stanley is author of a recent Issue Brief published by ACS entitled "The Crisis in Fourth Amendment Jurisprudence."
The privacy rights of Americans have come under a sustained assault in the past decade. In that time we have seen not only 9/11 attacks, but also a few additional, comparatively minor terrorist attacks, two wars, a constant stream of revolutionary new technologies, greatly expanded powers for our security agencies, and a relentless political drumbeat pounding on the supposed need to give those agencies even more powers to peer into our lives without due process or meaningful oversight.
Underlying all this, however, is a problem that pre-existed all of it: the fact that the Supreme Court's interpretation of the Fourth Amendment has gone badly off track. And that problem has intensified the erosion of our privacy caused by those other factors over the last 9 years.
The general consensus of a wide variety of commentators is that there are two principal problems with the Supreme Court's Fourth Amendment jurisprudence:
• The "third party doctrine," under which information shared with any third party loses all Fourth Amendment protection. Financial information held by your bank or medical information held by your doctor, for example has been exposed to a "third party," and under this doctrine is thus deemed to have been "given up" by you and therefore stripped of Fourth Amendment protection.
• The emergence of a circular standard of "reasonable expectation of privacy," under which Fourth Amendment protection only extends to those situations where an individual has an "expectation" of privacy that society is prepared to recognize as reasonable. As a result of this approach, the Fourth Amendment as it is currently interpreted provides no protection against a wide array of intrusive searches.
What's needed is a broad revival of the Fourth Amendment in American law.

But, in his TNR article, Pollack says 