A case against mass phone surveillance in US has been bolstered by a filing from American privacy group the Electronic Frontier Foundation (EFF) in a court of appeal.
Idaho nurse Anna Smith challenged data collection by the National Security Agency (NSA) following leaks by the whistleblower Edward Snowden last summer.
The EFF said: "The centrepiece of Mrs Smith’s case is the issue of whether the government’s collection of our telephone records in bulk, and retention of those records for five years, triggers the Fourth Amendment’s warrant requirement.
"The warrant requirement applies if there is a legitimate and reasonable expectation of privacy in those records. And if the warrant requirement applies, the collection is unconstitutional, since there is no warrant."
A district court previously dismissed Smith’s case based on third party doctrine, the notion that privacy cannot be expected if information has been entrusted to others, which the US government argues applies to certain types of phone data.
The Fourth Amendment to the US Bill of Rights protects Americans against unreasonable search and seizure, but has been subject to a number of exceptions since the US Constitution was ratified.
"Technological advances have vastly augmented the government’s surveillance power and exposed much more personal information to government inspection and intrusive analysis," the EFF added.
"If courts ignored this reality, the essential privacy long preserved by the Fourth Amendment would be eliminated."
The appeals court will convene on December 8 in Seattle, with Smith represented by her husband Peter, a professional attorney, alongside the EFF and the American Civil Liberties Union (ACLU).
