The US Court of Appeals for the District of Columbia Circuit [official website] on Friday declined [opinion, PDF] to rehear en banc a bid by the US Department of Justice (DOJ) [official website] to overturn a decision that prevents the government from using global positioning systems (GPS) technology to track suspects without a warrant. In a 5-4 vote, the court found that the petition [text, PDF] filed by the US Attorney General [official website] did not overcome the limitations of the automobile exception to the Fourth Amendment [text] warrant requirement. The court further rejected the argument that its previous ruling [JURIST report] frustrated the common practices sustained in visual and photographic surveillance of public places. Rather, the court noted that "this case does not require us to ... decide whether a hypothetical instance of prolonged visual surveillance would be a search subject to the warrant requirement of the Fourth Amendment." Chief Judge David Sentelle dissented, claiming that the court was ignoring precedent established by the US Supreme Court [official website] in United States v. Knotts [opinion, PDF], which allowed for electronic surveillance in public based on a lower expectation of privacy on public roads. The three-judge panel had distinguished the present case because too much personal information is revealed over longer periods of GPS surveillance.
Courts have struggled with how to apply Fourth Amendment protections to modern technology. In September, a three-judge panel for the US Court of Appeals for the Third Circuit [official website] ruled [opinion, PDF] that at times the government might need a warrant to obtain cell phone data [JURIST report] to track a person's location. In June, the US Supreme Court unanimously held [opinion, PDF] that, even if there is a reasonable expectation of privacy in work-issued electronic devices, that an employer's search of private text messages does not violate [JURIST report] the Fourth Amendment so long as the search is not excessive and is pursuant to a legitimate work-related purpose. Last year, the Ohio Supreme Court [official website] ruled [opinion, PDF] that police must obtain a warrant before searching data stored in a cell phone [JURIST report].