(CN) - A federal judge blasted the NSA's internet spying program Monday, saying he could not imagine a more arbitrary invasion of the American right to privacy that "the founders enshrined in the Fourth Amendment."
U.S. District Judge Richard Leon in Washington, D.C., wrote: "I cannot imagine a more 'indiscriminate' and 'arbitrary invasion' than this systematic and high-tech collection and retention of personal data on virtually every citizen for purposes of querying and analyzing it without prior judicial approval."
Rejecting the often-used political justification for the program, Leon also ruled that the Justice Department failed to prove that its collection of the so-called "telephony metadata" helped prevent terrorist attacks.
"Plaintiffs have a very significant expectation of privacy in an aggregated collection of their telephone metadata covering the last five years, and the NSA's Bulk Telephony Metadata Program significantly intrudes on that expectation," Leon wrote. "I have significant doubts about the efficacy of the metadata collection program as a means of conducting time-sensitive investigations in cases involving imminent threats of terrorism."
The ruling was in response to lawsuits brought by conservative activist Larry Klayman, who founded Judicial Watch, and Charles Strange, whose father, Michael Strange, was a cryptologist technician for the NSA and who was killed in Afghanistan when his helicopter was shot down in 2011.
Klayman and Strange were joined by two private investigators, Michael Ferrari and Matthew Garrison, in the lawsuit against the federal government and Facebook, Yahoo, Google, Microsoft, YouTube, AOL, PalTalk, Skype, Sprint, AT&T and Apple.
The American Civil Liberties Union filed a separate lawsuit in Manhattan Federal Court in June. The government faces a similar lawsuit in San Francisco, filed by a coalition of groups including Unitarian churches, gun-rights advocates and the Council on American-Islamic Relations.
The federal government has maintained that its collection of the phone data is supported by all three branches of government and is buoyed by the once-secret Foreign Intelligence Surveillance Court (FISC), where 15 different judges have issued 35 orders authorizing the program.
It's the first ruling against the spying program since former NSA contractor Edward Snowden leaked information about it in June.
Specifically, Snowden leaked to the media a FISC order from April 25 directing Verizon to turn over to the NSA on "an ongoing daily basis ... all call detail records or 'telephony metadata' created by Verizon for communications between the United States and abroad, or wholly within the United States, including local telephone calls."
"I cannot imagine a more 'indiscriminate' and 'arbitrary invasion' than this systematic and high-tech collection and retention of personal data on virtually every citizen for purposes of querying and analyzing it without prior judicial approval," Leon wrote. "Surely, such a program infringes on 'that degree of privacy' that the founders enshrined in the Fourth Amendment."
However, Leon stopped short of enforcing his order banning the NSA from continuing to collect the metadata pending a government appeal.
The Foreign Intelligence Surveillance Act allowed for secret courts to authorize government requests for data that might help with counterterrorism activities. The Patriot Act passed by Congress after the Sept. 11, 2001 terrorist attacks broadened the government's ability to collect information about Americans' phone activity.
It was only after Snowden leaked the information that the federal government admitted to its data collection practices.
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