The growing use by the police of new technologies that make surveillance easier and cheaper to conduct is raising difficult questions about the scope of constitutional privacy rights, leading to disagreements among judges.
As an example, a federal appeals court issued a ruling that contradicts precedents from three other appeals courts over whether police must obtain a warrant before secretly attaching a GPS device beneath a car. The issue is whether the Fourth Amendment’s protection against unreasonable searches covers a device that records a suspect’s movements for weeks or months without any need for an officer to trail him.
The GPS-tracking dispute coincides with a burst of other technological tools that expand police-monitoring abilities, including automated license-plate readers in squad cars, speed cameras mounted on streetlight poles and the widely discussed prospect of linking face-recognition computer programs to the proliferating number of surveillance cameras.
Some legal scholars say the escalating use of such high-tech techniques for enhancing traditional police activities is eroding the pragmatic considerations that used to limit how far a law-enforcement official could intrude on people’s privacy without court oversight. They have called for a fundamental rethinking of how to apply Fourth Amendment privacy rights in the 21st century.
Related questions have arisen over businesses’ customer records, which courts generally allow police to obtain without a warrant. The appeals court in Philadelphia is considering whether the Fourth Amendment protects location data for cellphones. The few Fourth Amendment cases involving contemporary technologies to reach the Supreme Court have generally stuck to the principle that privacy rights cover only actions no one else could normally see or hear.