Pure and simple. If we start violating the constitution and throw away our civil liberties, then we are worse than the terrorists. This country is founded on certain beliefs, and these must never be violated, even if it might make it a little easier to eavesdrop on terrorists. It makes it legal to eavesdrop on anyone, and that's wrong. We can't trust the government to have this kind of power, especially when they could apply for a warrant from the FISA court. The only reason they want to do this is so they can keep their activities secret from Americans, it has nothing to do with protecting us from from terrorists.