At the same time, policy makers must be aware of the phenomenon of “statutory mission creep”—in which the goals and missions of a program are expanded explicitly as the result of a specific policy action, such as congressional amendment of an existing law—and avoid its snares. In some instances, such as hospital emergency reporting systems, privacy interests may not be seriously compromised by their application to multiple missions. But in others, such as the use of systems designed for screening terrorists to identify ordinary criminals, privacy interests may be deeply implicated because of the vast and voluminous new data sets that must be brought to bear on the expanded mission. Mission creep may also go beyond the original understandings of policy makers regarding the scope and nature of a program that they initially approve, and thus effectively circumvent careful scrutiny. In some cases, a sufficient amount of mission creep may even result in a program whose operation is not strictly legal.


The rich digital record that is made of people’s lives today provides many benefits to most people in the course of everyday life. Such data may also have utility for counterterrorist and law enforcement efforts. However, the use of such data for these purposes also raises concerns about the protection of privacy and civil liberties. Improperly used, programs that do not explicitly protect the rights of innocent individuals are likely to create second-class citizens whose freedoms to travel, engage in commercial transactions, communicate, and practice certain trades will be curtailed—and under some circumstances, they could even be improperly jailed.

Protecting Privacy

Conclusion 1. In the counterterrorism effort, some degree of privacy protection can be obtained through the use of a mix of technical and procedural mechanisms.

The primary goal of the nation’s counterterrorism effort is to prevent terrorist acts. In such an effort, identification of terrorists before they act becomes an important task, one that requires the accurate collection and analysis of their personal information. However, an imperfect understanding of which characteristics to search for, not to mention imperfect and inaccurate data, will necessarily draw unwarranted attention to many innocent individuals.

Thus, records containing personal information of terrorists cannot be

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