Reuters | March 1, 2012
By Terry Baynes

(Reuters) - U.S. police can search a cell phone for its number without having a warrant, according to a federal appeals court ruling.

Officers in Indiana found a number of cell phones at the scene of a drug bust, and searched each phone for its telephone number. Having the numbers allowed the government to subpoena the owners' call histories, linking them to the drug-selling scheme.

One of the suspects, Abel Flores-Lopez, who was convicted and sentenced to 10 years in prison, argued on appeal that the police had no right to search the phone's contents without a warrant.

The U.S. Court of Appeal for the 7th Circuit rejected that argument on Wednesday, finding that the invasion of privacy was so slight that the police's actions did not violate the Fourth Amendment's ban on unreasonable searches.

The case gave the court an occasion to examine just how far police can go when it comes to searching electronic gadgets.

"Lurking behind this issue is the question whether and when a laptop or desktop computer, tablet, or other type of computer (whether called a 'computer' or not) can be searched without a warrant," Judge Richard Posner wrote for the three-judge panel.

He raised the example of the iCam, which allows someone to use a phone to connect to a home-computer web camera, enabling someone to search a house interior remotely.

"At the touch of a button, a cell phone search becomes a house search," he wrote.

Posner compared the cell phone to a diary. Just as police are entitled to open a pocket diary to copy an owner's address, they should be able to turn on a cell phone to learn its number, he wrote. But just as they're forbidden from examining love letters tucked between the pages of an address book, so are they forbidden from exploring letters in the files of a phone.

Prosecutors argued that in an age when people can wipe their cell phones clean remotely, officers are under pressure to obtain data before it is destroyed.

The court acknowledged that the actual risk that one of the suspects would have been able to destroy the phone's contents was minimal in this case. But so was the invasion of privacy, limited to telephone numbers.

The court left the question of just how far police can go in searching a phone's contents for another day.

A lawyer for Flores-Lopez was not immediately available for comment. (Reporting By Terry Baynes)