The thing often missed is we have absolutely no idea what has been stopped, you don't know if they stopped 50 attacks and just one succeeded. In some instances the 'bomber' may have been identified and stopped in some way, they may have infiltrated the supply chain of parts or countless other things. They can't publicise how they found their intelligence, if it is know how they operate it's makes it easier to evade. We just don't know, and that is a double edged sword especially when being critical of their powers. I fully appreciate all the arguments about how they operate and what they should and should not be able to do but there needs to be a balance and level of trust. If you were empowered with gathering intelligence what tools would you want? You are not fighting an army with a different uniform on the other side of the field here.