I agree congress does not have the need to know. Say for the sake of argument that NSA, through technical means, has tapped into a foreign IP address, and that IP address is yielding emails between a known terrorist and someone in the United States. Suppose these emails are yielding operational details about coming attacks here or overseas. NSA and the President would do everything to hide the existance of this intelligence source. Can you imagine telling congress details of this? More than likely we would read about it on the front page of the NYT. Even within the military and NSA, this type of info would not be shared outside of the individuals with a need to know.
Any leak at all about this and the source would be lost.
I think this is one reason why President Bush did not go back to the FISA court to get intercept authorization within 72 hours. The requests might be automatically approved,but I imagine some details must be given to the judge to justify the intercept. Why jeopardize the intelligence source, which is vital to national security?
I would guess that much of this intercepted data is acquired in bulk,from multiple sources, and must be sorted for key words, names, etc. It is probably not read in real time.
The leakers should be prosecuted. If the NYT committed a felony by publishing the information, they should be prosecuted as well.
You make a lot of sense in your message, and demonstrate an understanding of the situation.
Congress is not secure. Not at all. Never has been.