Laptop computers and other digital devices carried into the US may be seized from travellers without a warrant and sent to a secondary site for forensic inspection, the US Court of Appeals for the Ninth Circuit ruled last week.
The ruling is the second in less than a year that allows the US government to conduct warrantless, off-site searches of digital devices seized at the country's borders.
A federal court in Michigan last May issued a similar ruling in a case challenging the constitutionality of the warrantless seizure of a computer at the Detroit Metropolitan Airport. The defendant in a child pornography case also contended that a subsequent search of the device at a secondary computer forensic facility violated the Fourth Amendment of the Constitution.
Several other courts, including the Ninth Circuit itself, have ruled that warrantless, suspicion-less searches of laptops and other digital devices can take place at US border locations.
The issue of border searches is an important one for businesses because corporate travellers often carry laptops holding sensitive company data across US borders.
Privacy advocates and travel groups have expressed concern that searches of such laptops could expose such sensitive corporate or customer information, especially citing the Department of Homeland Security's policy of copying or downloading the data if necessary.
The American Civil Liberties Union (ACLU) said that according to government documents it has obtained, US customs officials searched electronic devices belonging to about 6,600 travellers between October 2008 and June 2010. The ACLU also said that US officials confiscated more than 220 devices between October 2008 and June 2009.
The Ninth Circuit court ruled on an appeal filed by the government in a case against Howard Cotterman, who was charged with producing, shipping and transporting child pornography based on evidence gathered from his laptop computers.
Cotterman's laptops were seized at a border crossing in Lukeville, Arizona, upon his return to the country from a visit to Mexico. Custom officials decided to inspect Cotterman's computers because their computer systems showed he was a registered sex offender in California.
Officials found no incriminating data in an initial inspection of Cotterman's computers and a digital camera at the border. However, because many of the files on the computers were password protected, the agents decided to transport the systems to a digital forensics laboratory 170 miles away in Tucson.
Lab personnel copied all the content on Cotterman's hard drives and used forensic analysis tools to analyse it. The search of the drives yielded hundreds of images depicting child pornography, authorities said.
Cotterman was later arrested and indicted on several charges related to child pornography.
Cotterman filed a motion asking that the evidence found by lab personnel be suppressed because it had been gathered in violation of his Fourth Amendment right against unreasonable search.
A magistrate judge and a district court judge concurred with Cotterman and held that the government needed to have a specific suspicion to conduct such an extended search. The judges ruled that since customs agents did not have any reasonable suspicion that contraband would be found on Cotterman's computers, they violated his Fourth Amendment rights.
In its appeal, the government contended that the border search doctrine allows such actions even without reasonable suspicion or cause.
In upholding that argument, the Ninth Circuit court noted that several other courts and even the US Supreme Court have consistently recognised that all border searches are reasonably simply because they occur at the border.
"The sticking point is whether the inherent power of the government to subject incoming travellers to inspection before entry also permits the government to transport property not yet cleared for entry away from the border to complete its search," Judge Richard Tallman wrote for the majority opinion.
In this case, Tallman ruled that such transportation is justified because the forensic tools need to adequately search the computers were located at another facility.
"The border search doctrine is not so rigid as to require the United States to equip every entry point - no matter how desolate or infrequently travelled - with inspectors and sophisticated forensic equipment," Tallman said in his ruling.
In situations where "logic and practicality" may require equipment presented at the border to be transported to another location, the government needs to show no "heightened suspicion" to justify it, the court ruled.