The NSA and other US intelligence agencies exist to protect the United States from all enemies, foreign and domestic. It has become fashionable to opine that civil liberties are deteriorating in the United States, but that is a notion not supported by fact.
Contrary to what many people believe, the US government has no interest in your personal phone calls, email, library books, or other aspects of your personal life unless you are communicating with known terrorists or planning a terrorist attack yourself. The surveillance programs are aimed at the very real threat of terrorist cells, both those abroad and hidden among us, not your plans for the weekend or your conversations with your spouse.
The NSA's so-called "warrantless wiretap" program is actually on solid legal ground. The Foreign Intelligence Surveillance Act of 1978 provided a secret court to issue warrants for surveillance. It also specifically allows the President to authorize warrantless wiretaps if "there is no substantial likelihood that the surveillance will acquire the contents of any communication to which a United States person is a party". (50 U.S.C. 1802(a)(1)). Additionally, FISA also contains a provision that states that FISA is to apply "unless authorized by statute."
Congress' Authorization To Use Military Force Against Terrorist provides just such a statutory exception. The Authorization states in part that the president may "use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons." Such an authorization would reasonably include intelligence gathering operations to prevent future attacks.
The Bush Administration advised members of both parties of Congress about the nature of the surveillance program. In doing so, they complied with their duty to notify Congress under the National Security Act of 1947. These notifications also seem to indicate that the Bush Administration fully believed that the program was legal. A Congressional Research Service report states that limited notifications were permitted to protect intelligence gathering methods.
It is also interesting to note that none of the members of Congress who were notified were reported to have any problems with the surveillance program prior to its publication in the New York Times.
The Bush Administration is caught between a rock and a hard place with their critics. When an attack occurs, they are criticized for intelligence failures and for not doing enough to stop the terrorists. When they do take strong and decisive actions to go on the offensive against the terrorists, they are criticized for curtailing civil liberties.
The NSA's domestic surveillance programs are not a threat to civil liberties, but a valuable tool in the war against the terrorists. Making these programs public was a great disservice to the nation and makes it harder for our military and law enforcement personnel to do their jobs. I would be much more concerned if our government were not listening on the conversations of terrorists.