Here are the last two paragraphs of an excellent post today by John Dean (Findlaw's Writ):
"Bush's unauthorized surveillance, in particular, seems very likely to be ineffective. According to experts with whom I have spoken, Bush's approach is like hunting for the proverbial needle in the haystack. As sophisticated as NSA's data mining equipment may be, it cannot, for example, crack codes it does not recognize. So the terrorist communicating in code may escape detection, even if data mining does reach him.
"In short, Bush is hoping to get lucky. Such a gamble seems a slim pretext for acting in such blatant violation of Congress' law. In acting here without Congressional approval, Bush has underlined that his Presidency is unchecked - in his and his attorneys' view, utterly beyond the law. Now that he has turned the truly awesome powers of the NSA on Americans, what asserted powers will Bush use next? And when - if ever - will we - and Congress -- discover that he is using them?"