After years of winning court tests of its surveillance activities, the National Security Agency lost a big one today, per this report from Politico‘s Josh Gerstein:

A federal judge ruled Monday that the National Security Agency program which collects information on nearly all telephone calls made to, from or within the United States is likely unconstitutional.

U.S. District Court Judge Richard Leon found that the program appears to violate the Fourth Amendment ban on unreasonable searches and seizures. He also said the Justice Department had failed to demonstrate that collecting the information had helped to head off terrorist attacks.

Leon stayed implementation of his grant of relief from surveillance to let the government pursue an appeal to the D.C. Circuit. But it’s a pretty big blow to the NSA.

Independent since 1969.

The Washington Monthly is nonprofit and reader-supported. Your tax-deductible gift pays for the reporting you just read.

Ed Kilgore, a contributing editor of the Washington Monthly, is a columnist for New York.