Earlier quoted context omitted.
Who says the cost is purely economic? What is the value of the first and fourth amendments to americans?
Intercepting messages doesn't violate the First Amendment. Intercepting messages with either "reasonable" means or "unreasonable means + probable cause warrant" also doesn't violate the Fourth Amendment. So I wouldn't necessarily make your sole complaint about the legality of the program, as it may very well soon be both legal and Constitutional.
What about all that stuff about chilling effects and anonymous speech?