The Obama administration has acknowledged that it is collecting a massive amount of telephone records from at least one carrier, reopening the debate over privacy as it defended the practice as necessary to protect Americans against attack.

The admission comes after the Guardian newspaper published a secret court order related to the records of millions of Verizon Communications customers on its website yesterday.

A senior administration official said the court order pertains only to data such as a telephone number or the length of a call, and not the subscribers’ identities or the content of the telephone calls.

Such information is “a critical tool in protecting the nation from terrorist threats to the United States”, the official said, speaking on the condition of not being named.

“It allows counter-terrorism 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 official added.

Fresh concerns

The revelation raises fresh concerns about President Barack Obama’s handling of privacy and free speech issues. His administration is already under fire for searching Associated Press journalists’ calling records and the emails of a Fox television reporter as part of its inquiries into leaked government information.

It was not immediately clear whether the practice extends to other carriers.

The order released yesterday is from the US Foreign Intelligence Surveillance Court and directs Verizon’s Business Network Services Inc and Verizon Business Services units to hand over daily electronic data until July 19th.

The classified order revealed last night said the Obama administration is secretly carrying out a domestic surveillance programme under which it is collecting business communications records involving Americans under a hotly debated section of the Patriot Act.

The order, signed by Judge Roger Vinson of the Foreign Intelligence Surveillance Court in April, directs a Verizon Communications subsidiary, Verizon Business Network Services, to turn over “on an ongoing daily basis” to the National Security Agency all call logs “between the United States and abroad” or “wholly within the United States, including local telephone calls”.

Verizon Business Network Services is one of the nation’s largest telecommunications and internet providers for corporations. It is not clear whether similar orders have gone to other parts of Verizon, such as its residential or cellphone services, or to other telecommunications carriers. The order prohibits its recipient from discussing its existence, and representatives of both Verizon and AT&T declined to comment yesterday evening.

Government surveillance

The disclosure late yesterday seemed likely to set off a new furore over the scope of government surveillance.

Kate Martin of the Center for National Security Studies, a civil liberties advocacy group, said that “absent some explanation I haven’t thought of, this looks like the largest assault on privacy since the NSA wiretapped Americans in clear violation of the law” under the Bush administration.

“On what possible basis has the government refused to tell us that it believes that the law authorises this kind of request?” she said.

For several years, two Democrats on the Senate Intelligence Committee, senator Ron Wyden of Oregon and senator Mark Udall of Colorado, have been cryptically warning that the government was interpreting its surveillance powers under that section of the Patriot Act in a way that would be alarming to the public if it knew about it.

“We believe most Americans would be stunned to learn the details of how these secret court opinions have interpreted section 215 of the Patriot Act,” they wrote last year in a letter to Attorney General Eric H Holder jnr.

They added: “As we see it, there is now a significant gap between what most Americans think the law allows and what the government secretly claims the law allows. This is a problem, because it is impossible to have an informed public debate about what the law should say when the public doesn’t know what its government thinks the law says.”

Reuters/New York Times service