Do Warrants Matter?

The recently-disclosed Terrorist Surveillance Program (TSP) has caused debate over whether warrants should be required for wiretaps targeting international terrorism. We examine traditional criminal wiretaps to determine whether the warrant requirement limits law enforcement. We find budget constraints cause law enforcement to pursue only taps that are particularly likely to succeed. Thus, eliminating the warrant requirement for traditional wiretaps would matter little, and the significance of a warrant requirement for the TSP depends on budget. If the program is well-funded, a warrant requirement will deter marginal taps, but if the program is lightly funded, a warrant requirement is superfluous