Nobody has done more streling service in defense of liberty in the face of Bushist lawlessness than Glenn Greenwald. He's well worth reading.
Today he zeroes in on the real point of the FISA controversy:
One other vital point: The claim that telecoms will cease to cooperate without retroactive immunity is deeply dishonest on multiple levels, but the dishonesty is most easily understood when one realizes that, under the law, telecoms are required to cooperate with legal requests from the government. They don't have the option to "refuse." Without amnesty, telecoms will be reluctant in the future to break the law again, which we should want. But there is no risk that they will refuse requests to cooperate with legal surveillance, particularly since they are legally obligated to cooperate in those circumstances. The claim the telcoms will cease to cooperate with surveillance requests is pure fear-mongering, and is purely dishonest.