The sessions scheduled for Wednesday afternoon on Capitol Hill were to be led by the NSA's director, Lt. Gen. Keith B. Alexander, and were sure to focus on the ultra-secret agency's efforts to monitor domestic calls when one party is overseas and suspected of terrorism, as well as the agency's efforts to collect records on ordinary Americans' calls.
The briefings were coming less than 24 hours ahead of the opening of confirmation hearings for Gen. Michael Hayden, nominated to head the CIA. He was set to appear Thursday before the Senate Intelligence Committee.
It seems the White House is hoping to alleviate tensions surrounding Hayden's nomination. As CBS News correspondent Gloria Borger reports, if you ask questions in a private classified briefing, you cannot ask them again in an open hearing.
Sen. Pat Roberts, R-Kan., the Intelligence Committee chairman, said it became apparent that his entire committee needed to understand the NSA program in advance of having a full hearing on Hayden, who headed the NSA from 1999 until 2005.
"There was no way we could fulfill our collective constitutional responsibilities without that knowledge," Roberts said.
Roberts tells Borger that the NSA was looking at the phone calls collected during the surveillance, but he said not at the content, just at the pattern of phone calls.
Previously, only select members of the House and Senate intelligence committees were briefed in detail on the program. Democrats have been pressing the White House to provide the information to the full committees since December, saying that to do otherwise was a violation of the 1947 National Security Act.
"The White House, for the first time, is showing signs that they are serious about oversight of this program," said West Virginia Sen. Jay Rockefeller, the intelligence committee's top Democrat.
Rep. Jane Harman, D-Calif., Rockefeller's House counterpart, said: "It's a shame that it took an endangered nomination to make this happen."
Also on Wednesday, a federal judge ruled that secret documents that allegedly detail the surveillance of AT&T phone lines under the Bush administration's domestic spying program , but the records will remain sealed.
Meanwhile, Verizon Communications Inc. says it did not give the government records of millions of phone calls, joining fellow phone company BellSouth in disputing key assertions in a USA Today article.
The denials leave open the possibility that the NSA requested customer calling data from long-distance companies like AT&T, Sprint and MCI in 2001, but not from companies that were mainly local phone companies, such as Verizon.
President Bush, however, insisted Tuesday that no domestic phone calls were ever listened to without a warrant, CBS News correspondent Jim Stewart reports.
Read Verizon's Statement
Read BellSouth's statement
"This government will continue to guard the privacy of the American people," Mr. Bush said at the White House. "But if al Qaeda is calling into the United States, we want to know. And we want to know why."
Mr. Bush declined to specifically discuss the compiling of phone records, or whether that would amount to an invasion of privacy.