A federal judge in Houston has ruled that authorities need a search warrant to obtain cellphone records that can be used to track a person's movements.
U.S. District Judge Lynn Hughes's one-page order upheld a magistrate judge's 2010 ruling that had denied a request by federal authorities in three separate criminal investigations to compel cellphone companies to provide _ without a search warrant _ 60 days of records for several phones.
Hughes said in his ruling the data authorities requested is constitutionally protected from intrusion and can only be acquired with a search warrant under the Fourth Amendment, which protects against unlawful search and seizure.
In the 2010 ruling, U.S. Magistrate Judge Stephen Smith had ruled the warrantless request by authorities violated the Fourth Amendment.
The cellphone data authorities had requested was being sought under the Stored Communications Act, part of the Electronics Communications Privacy Act, and that information is often given without a search warrant.
In court documents, prosecutors had argued a search warrant was not needed because obtaining such cellphone information "is not a Fourth Amendment search" and is "neither invasive nor intrusive."
Hughes disagreed in his ruling, which was issued Nov. 11 and made public earlier this week.
"The standard under the Stored Communications Act is below that required by the Constitution," Hughes said.
Angela Dodge, a spokeswoman for the U.S. Attorney's Office in Houston, said the office is "considering all of our legal options" in regards to Hughes' ruling.
Officials with the American Civil Liberties Union, which had filed legal briefs in the case asking that Smith's original ruling be upheld, were pleased by Hughes' decision, calling it good news for everyone who carries a cellphone.
Catherine Crump, a staff attorney with the ACLU, said cellphones create a record of people's movements, which can reveal private information about the phone's user as well as information about that person's friends and family.
"This is precisely the sort of private, sensitive information that the government should not be able to access without getting a warrant," Crump said. "The Fourth Amendment is designed to protect people from unreasonable searches and seizures. How courts interpret that amendment must keep pace with new technologies if its protections are to have any meaning."
Other judges around the country have also issued similar rulings, which have stirred debate about whether search warrants should be mandatory to obtain such cellphone data and debate about whether the Electronics Communications Privacy Act needs to be revamped.
In August, a federal judge in New York ruled a search warrant was needed for cell-site-location records. In 2010, a Pennsylvania federal appeals court ruled judges have the right to require warrants before police get cell phone records that could suggest a customer's likely location.