Kevin Drum offers the suggestion that since just about everyone involved in this fiasco has mentioned some sort of technical or technological imperative in defense of their actions that maybe the NSA has some sort of new data-mining capability that goes beyond our notion of wiretapping.  As Kevin notes, however, the key question is this:

"What kind of program is so intrusive that even Republicans, even with 9/11 still freshly in mind, wouldn't have supported it?"

Better yet, another question might be:

"Since the Bush Administration can count on Congressional Republicans to neither criticize nor investigate its actions, what threshold of illegality does that same Administration have to pass for Congressional Republicans to actually do something about it?"