A judge rules the U.S. government's gathering of Americans' phone records likely is unlawful.
U.S. District Judge Richard Leon of the District of Columbia ordered the suspension of the collection of data on two phone company customers who sued the Obama administration.
The ruling marks a significant challenge to U.S. spying authority.
In his written opinion, the judge said that the government's program likely violated Americans' right to be free of unreasonable searches.
The U.S. Justice Department is reviewing the ruling - and said in a statement quote: "We believe the program is constitutional as previous judges have found."
In June, the British newspaper the Guardian reported that a U.S. surveillance court had secretly approved the collection of millions of raw daily phone records - after former National Security Agency contractor Edward Snowden leaked the program.
