On quite a few occasions Bush asserted defiantly that wiretapping required court orders. It was a rather odd line to make its way into a speech, and now we know he kept saying it because he was disobeying the law.
He subsequently claimed that this was a limited program which only operated on people who had links to terrorism and who were getting phone calls from al Qaeda. This, of course, was untrue on its face as there is no way they'd have problems getting warrants from the FISA court for such things.
Now we know the program involved illegally spying on large numbers of innocent people with no connections to terrorism.
Through all of this the question really has been -- why? None of the claims by Bush defenders have held up at all. The only reason I can come up with that makes any sense is that if you institute a program which illegally spies on large numbers of innocent people it's much easier to hide the real targets of the operation.