I was refering to the liberty costs, not the monetary costs. The monetary costs are approved by Congress, not the Executive, that is, the representatives of the people. As far as cost, I'm sure you would be surprised at the amount of money spent on defense that has no pblic accountability and the funding remains classified. Yet it is absolutely necessary to the defense of the United States.
in addition, you seem to have no understanding of what power this would grant them. you also state that it wouldn't cost anything. that's incorrect. the infrastructure is already in place for the most part on search engines, granted. but email is a different story. to capture all of that traffic, they'd have to install black boxes at every ISP. they'd also have to lease/install lines for the bandwidth to the processing facilities. this could, in essence, create a network on the scale of the US's portion of the internet itself. it'd cost billions, depending on how far they took it.
You make it sound as if someone is reading you email. Believe me, they don't care. Computers mine data for patterns that identify terrorists. I really don't understand your concern. What are you afraid of? Why do you want to undermine proven technlogy that saves Americans lives?
also, having that infrastructure in place would allow them to have access to every electronic communication from anyone anywhere in the U.S. even if they say they are just looking at email traffic, they'd still have to sift through *everything* to find it...and they'd have access to *everything*.