Powerline has an extensive and excellent review of the legal foundation for the legality of the big news story of the week.

John Hinderaker offers an in-depth look at several decisions which will have an effect on this story. Please read the whole thing, but here is his ultimate conclusion:

There is no mystery about the legality of the NSA intercept program. It is intended to capture foreign intelligence information, including information about potential terrorist threats, and as such, every federal court that has addressed the issue has held that it is within the inherent constitutional power of the President as Commander in Chief. Everything else is immaterial.

This brings us back where we started, i.e. , the Constitution. The only constitutional limitation on the President’s power to intercept communications by Americans for national security purposes is that such intercepts be “reasonable.” Is it reasonable for the administration to do all it can to identify the people who are communicating with known terrorists overseas, via the terrorists’ cell phones and computers, and to learn what terrorist plots are being hatched by those persons? Is it reasonable to do so even when—rather, especially when--some portion of those communications come from people inside the United States? I don’t find it difficult to answer those questions; nor, if called upon to do so, would the Supreme Court.

Like I said....read the whole thing.

UPDATE: The DOJ apparently reads Powerline, since they have sent this justification to the Congress. The conclusion?

"Intercepting communications into and out of the United States of persons linked to al Qaeda in order to detect and prevent a catastrophic attack is clearly reasonable. Reasonableness is generally determined by "balancing the nature of the intnision on the individual's privacy against the promotion of legitimate governmental interests.""

Amen.

UPDATE II: Mark Levin in the Corner recommends that people should read up on the 4th Amendment and Search & Seizure...

UPDATE III: Lifelike Pundits points to a fairly disturbing, though not unexpected, editorial from the senior beached whale....errr....Senator from Massachussetts. Displaying either astonishing ignorance, or blatant dishonesty (both are compelling), Kennedy states:

The president is the commander in chief of the military. That doesn't give him the power to spy on civilians at home without any judicial oversight whatsoever, without ever revealing those activities to even well-established courts that review these matters in secrecy. Otherwise, every phone and computer in America should now come with a warning label: Warning: the privacy of your communications can no longer be guaranteed, by order of President Bush.

Obviously he is shut up in his parlour enjoying some (or a lot of) holiday brandy...otherwise he would know that this was targeted at specific people with connections to terrorism, not random American citizens. Of course admitting that won't play as well with the tinfoil crowd. Ironically, Kennedy takes great pride in being the father of FISA....

Years ago, with bipartisan support, I spearheaded the passage of the Foreign Intelligence Surveillance Act (FISA), which specifically requires the attorney general to obtain prior authorization from a judge, in a secret expedited proceeding, before engaging in domestic spying or wiretapping.

Funny, if he was so intimately involved with FISA he would know that there are provisions for warrantless efforts (see Powerline above).

Lastly (and revealing his dishonesty) he tries to draw a connection between this issue, and a tinfoil urban myths connected with the Patriot Act.

Think of the chilling effect on free speech and academic freedom when a government agent shows up at your home -- after you request a book from the library. Incredibly, we are now in an era where reading a controversial book may be evidence of a link to terrorists.

A truly shameful performance that deserves a big smackdown....