(CNN) -- The U.S. government has obtained a top secret court order that requires Verizon to turn over the telephone records of millions of Americans to the National Security Agency on an "ongoing daily basis," the UK-based Guardian newspaper reported.
The four-page order, which The Guardian published on its website Wednesday, requires the communications giant to turn over "originating and terminating" telephone numbers as well as the location, time and duration of the calls -- and demands that the order be kept secret.
If genuine, it gives the NSA blanket access to the records of millions of Verizon customers' domestic and foreign phone calls made between April 25, when the order was signed, and July 19, when it expires.
While the report infuriated people across the country -- former Vice President Al Gore called the idea "obscenely outrageous" -- a senior official in the Obama administration defended the idea of such an order early Thursday.
Without acknowledging whether the order exists, the administration official emphasized that such an order does not include collection of "the content of any communications or the name of any subscriber. It relates exclusively to metadata, such as a telephone number or the length of a call."
"Information of the sort described in the Guardian article has been a critical tool in protecting the nation from terrorist threats to the United States, as it allows counterterrorism personnel to discover whether known or suspected terrorists have been in contact with other persons who may be engaged in terrorist activities, particularly people located inside the United States," the unnamed official said in a written statement to media.
The official also insisted that the Foreign Intelligence Surveillance Act authorizes intelligence collection. Activities "are subject to strict controls and procedures under oversight of the Department of Justice, the Office of the Director of National Intelligence and the FISA Court, to ensure that they comply with the Constitution and laws of the United States and appropriately protect privacy and civil liberties."
That response was unlikely to quell the quickly growing criticism.
"While I cannot corroborate the details of this particular report, this sort of widescale surveillance should concern all of us and is the kind of government overreach I've said Americans would find shocking," said Sen. Mark Udall, D-Colorado, who serves on the Senate Intelligence Committee.
Gore, in a tweet, also criticized the move.
"In the digital era, privacy must be a priority. Is it just me, or is secret blanket surveillance obscenely outrageous?" he said.
Verizon spokesman Edward McFadden declined to comment on the report.
According to the document published by The Guardian, Judge Roger Vinson of the Foreign Intelligence Surveillance Act (FISA) Court signed a "secondary order" granting an FBI request for access to the records.
The FBI did not respond to a CNN request for comment. The NSA told CNN it will respond "as soon as we can."
The order does not say why the request was made, but it bans the government and Verizon from making the contents public.
It says the order will be declassified in April 2038.
Analyst: How the order might help fight terrorism
Former FBI Assistant Director Tom Fuentes, a CNN contributor, suggested one way such an order might help fight terrorism.
"If a phone number comes up being connected to someone of suspicion, then (investigators) can go back and look at all of the numbers that phone number called or was called by, how long the calls were, what location the calls were made from, that type of information," he said on CNN's "Starting Point."
"It's not that someone or some group of analysts can sit there and monitor 50 million phone calls going through the computers. But it would create the ability to go back and see if you could connect phone calls."
For example, he said, it could allow investigators to go back and look at phone records of Boston bombing suspect Tamerlan Tsarnaev. Normally, phone companies would not maintain those records for long due to storage capacity, Fuentes said. With such an order, the records will be maintained by the NSA and "held for future investigations."
But some organizations that track privacy issues say they're unaware of the government having ever taken such sweeping action.
"As far as we know, this order from the FISA court is the broadest surveillance order to ever have been issued: it requires no level of suspicion and applies to all Verizon subscribers anywhere in the U.S.," the Center for Constitutional Rights said in a statement.
The American Civil Liberties Union called for an immediate end to the order and a congressional investigation.
"It's a program in which some untold number of innocent people have been put under the constant surveillance of government agents," said Jameel Jaffer, the ACLU's deputy legal director.
"It is beyond Orwellian, and it provides further evidence of the extent to which basic democratic rights are being surrendered in secret to the demands of unaccountable intelligence agencies."
It is not the first time such an action has been taken.
In 2006, it was revealed that the NSA was secretly collecting telephone records as part of an effort to root out potential terror plots.
At that time, Verizon denied reports that it was providing the NSA with data from customers' domestic calls. The company said that while it is committed to helping the government protect against terrorist attacks, "we will always make sure that any assistance is authorized by law and that our customers' privacy is safeguarded."
The news about the Verizon order comes as the Obama administration is under fire following revelations that the Justice Department seized two months of telephone records of a number of Associated Press reporters and editors, saying the requests were part of an investigation into the leak of classified information.
Justice officials haven't specified the leak that triggered the probe, but the AP has said it believes the investigation focuses on its account of a foiled plot to bomb a U.S. airliner in May 2012.