After thinking about the NSA domestic intercepts program, I have decided that much of the discussion of this subject misses the point about what has changed in communications surveillance in this country.
Before 9/11 (with a few exceptions) domestic communications surveillance was a matter for the police (FBI et al) under the supervision of the courts. The police were required to provide the appropriate judge evidence which supported the need to inspect someones communication in preparation for a possible court proceeding against that person. The writs issued by such judges had expiration dates and the police were forced by the law to return to the courts periodically to obtain extensions. The police did not particularly like that because it was inconvenient to them, and the police (like everyone else) want to have their lives made as simple and safe as possible. A lot of them would also like to have the citizenry deprived of the right to own guns, a similar thing. Nevertheless, this whole system was part of our JUDICIAL system.
The National Security Agency (NSA) is not part of the judicial system. It grew out of World War 2 codebreaking activities on the part of the armed forces (Enigma, etc.) and continued to grow like the Hydra throughout the Cold War. American government found large scale "exploitation" of Soviet electronic signals to be a comprehensible and worthwhile endeavor, something much more to American taste than the messy, more morally ambiguous business of espionage (HUMINT).
It seems to me that all the talk of warrants and the FISA law is irrelevant. The decision to use NSA against US domestic communications had nothing to do with the courts or the FISA law. It was simply a decision to tell NSA to turn its antennae inward rather than outward. NSA is essentially a military organization although it employs many civilians. It is part of the Department of Defense (DoD). When given an order, it obeys with no quibbling about court orders, warrants, writs, expiration dates, justification. etc.
Having been told to perform such operations, NSA and other element of DoD will simply continue them indefinitely, receiving tasking from intelligence centers and consumers routinely and collecting information as they did for half a century against the Soviets. "Consumers?" Hmmm…
This leaked to the press because people at NSA decided that their professional habit of silence was trumped by the implications of this massive a change in the privacy rights of Americans.