NSA headquarters (Getty Images)

A federal judge has ruled that the National Security Agency’s practice of collecting the telephone metadata of billions of calls made to and from the United States is likely a violation of the Fourth Amendment to the Constitution.

“I cannot imagine a more ‘indiscriminate’ and ‘arbitrary invasion’ than this systematic and high-tech collection and retention of personal data on virtually every single citizen for purposes of querying it and analyzing it without judicial approval,” U.S. District Court Judge and George W. Bush appointee Richard Leon wrote [PDF]. “The government does not cite a single instance in which analysis of the NSA’s bulk metadata collection actually stopped an imminent attack, or otherwise aided the Government in achieving any objective that was time-sensitive in nature.”

While Judge Leon issued an injunction that prevents the NSA from continuing to collect the data, he stayed it in order to allow the government to appeal, and stopped short of issuing a final determination on the program’s constitutionality. Judge Leon has previously signaled that he believes the case will reach the U.S. Supreme Court.

A DOJ spokesman told Politico that they were “reviewing the court’s decision.”

The case was brought before the judge (who also sentenced former D.C. Council Chair Kwame Brown to 480 hours of community service for lying on bank loan forms) by conservative attorney and birther Larry Klayman.

The Times has Edward Snowden’s reaction to the ruling:

I acted on my belief that the N.S.A.’s mass surveillance programs would not withstand a constitutional challenge, and that the American public deserved a chance to see these issues determined by open courts. Today, a secret program authorized by a secret court was, when exposed to the light of day, found to violate Americans’ rights. It is the first of many.