“Months after the Sept. 11 attacks, President Bush secretly authorized the National Security Agency to eavesdrop on Americans and others inside the United States to search for evidence of terrorist activity without the court-approved warrants ordinarily required for domestic spying, according to government officials.
Under a presidential order signed in 2002, the intelligence agency has monitored the international telephone calls and international e-mail messages of hundreds, perhaps thousands, of people inside the United States without warrants over the past three years in an effort to track possible "dirty numbers" linked to Al Qaeda, the officials said. The agency, they said, still seeks warrants to monitor entirely domestic communications.” NY Times
This may have been a criminal act on the part of the president. The law which created the National Security Agency is pretty clear. NSA is about listening in on FOREIGN communications, not US domestic communications. There is an exception in the law that would allow NSA to be used for this purpose in exceptional circumstances and with the issuance of a writ by the Foreign Intelligence Surveillance Court (FISA). Information so far does not indicate that this procedure was followed.
Congress is not happy. This probably played some role in defeat of the re-authorization of the Patriot Act.
It appears that Mr. John Yoo took the position while in government that in wartime the president of the USA could do whatever he liked.