balanced by judicial or any other kinds of review, leaving the individual at a severe disadvantage when information is inaccurate or incomplete.2

None of these concerns about balancing the need for law enforcement agencies to gather information and the need of the citizen for privacy are new. What is new are the modern information technologies that law enforcement agencies can now use to observe situations and identify individuals more quickly, more accurately, and at less expense than ever before. These technologies include surveillance cameras, large-scale databases, and analytical techniques that enable the extraction of useful information from large masses of otherwise irrelevant information.

The sections that follow describe a number of technologies that allow law enforcement agencies expanded capabilities to observe, to listen, and to gather information about the population. Just as the ability to tap phone lines offered law enforcement new tools to gather evidence in the past century, so also these new technologies expand opportunities to discover breaches in the law, identify those responsible, and collect the evidence needed to prosecute. And just like the ability to tap telephones, these new technologies raise concerns about the privacy of those who are—rightly or wrongly—the targets of the new technologies. Use of the technologies discussed requires careful consideration of the resulting tension posed between two legitimate and sometimes competing goals: information gathering for law enforcement purposes and privacy protection.

Technology and Physical Observation

As a point of departure, consider the issue of privacy as it relates to government authorities conducting surveillance of its citizens. Using the anchoring vignette approach described in Chapter 2 (see Box 2.2), a possible survey question might be, How much does [your/“Name’s”] local town or city government respect [your/“Name’s”] privacy in [your/her/his] routine local activities? Here are a number of possibilities:

  1. [Anita] lives in a city that prohibits any form of video or photographic monitoring by government agencies.

  2. [Bita] commutes to work every day into a city that automatically photographs each car to see whether it runs a particular stoplight.

  3. [Jake] lives in a city that videotapes all cars on city-owned property.


See, for example, Peter M. Shane, “The Bureaucratic Due Process of Government Watch Lists,” Ohio State Public Law Working Paper No. 55, February 2006, available at

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