Bruce Schneier's recent piece "The Erosion of Freedom" has generated a reaction, to which he has responded with "Limitations on Police Power Shouldn't Be a Partisan Issue." Schneier mentions "the USA Patriot Act and other laws" and explains how "they represent an enormous increase in police power in the United States" by illustrating what he identifies as "four principles that should guide our use of personal information by the police:"
The first is oversight: In order to obtain personal information, the police should be required to show probable cause, and convince a judge to issue a warrant for the specific information needed.
Second, minimization: The police should only get the specific information they need, and not any more. Nor should they be allowed to collect large blocks of information in order to go on "fishing expeditions," looking for suspicious behavior.
The third is transparency: The public should know, if not immediately then eventually, what information the police are getting and how it is being used.
And fourth, destruction. Any data the police obtains should be destroyed immediately after its court-authorized purpose is achieved. The police should not be able to hold on to it, just in case it might become useful at some future date.