The full extent of the administration's surveillance, data mining and similar programs isn't clear. Financial institutions have been reporting activities that they consider suspicious to the Department of Homeland Security. In one case, a Rhode Island retiree was flagged as suspicious after he made an unusually large payment — $6,522 — on his MasterCard.

In other cases, FBI or Secret Service agents have investigated e-mails or Internet postings that suggested possible threats to Bush or to national security.

The Pentagon launched a Total Information Awareness program to mine a wide variety of electronic databases, but Congress shut it down in 2003. However, former government officials said that the Defense Department merely shifted the program to the NSA's Advanced Research and Development Activity under code names that have included "Basketball" "Genoa II" and "Topsail."

In 2004, the Government Accountability Office, the investigative arm of Congress, reported that the government had or was developing more than 120 programs to collect and analyze large amounts of electronic personal data.

"It makes no sense to look at millions of phone records and not look at the kind of communications that terrorists actually use," said a former senior U.S. intelligence official, who spoke only on the condition of anonymity because he has knowledge of numerous classified programs. "That means e-mail and Web sites, and it means all kinds of travel and credit card records, because (al-Qaida leader Osama) bin Laden uses couriers to deliver most of his messages."

Critics said turning over information about phone calls infringes on personal privacy even if the government doesn't listen to the conversations.

"As soon as you know what numbers somebody is calling, how many times, you know a lot," said Jim Harper, director of information policy at the Cato Institute, a libertarian policy-research center. "They might be to your priest. They might be to your doctor. They might be to your paramour."

Harper, an expert on data mining and communications intercepts, said the NSA could apply the same methods to cellular phone calls and e-mail messages.

The American Civil Liberties Union said the revelations underscored the need for a full congressional investigation into NSA eavesdropping.

"The government is clearly tracking the calls and communications of millions of ordinary Americans and that's just plain wrong," said ACLU Executive Director Anthony Romero.

"They want to be able to grab everything and then sift through what's of interest," said lawyer Lee Tien of the Electronic Frontier Foundation, another civil liberties group. "The idea is that you get everybody just to get a few. It just feels un-American."