Echelon is a targeted system used by the western allied intelligence agencies, the newer system put in place to watch the US's borders is a far more powerful tool and will deliver all traffic rather than just traffic originating from A to B on a watch-list, its scope is far more powerful and intrusive.
The real problem for any democracy relying on such systems to stay one leap ahead is that over time such methods become less effective as methods are found to bypass such surveillance and thus one could argue that to build even bigger systems to provide a small improvement over the old system is actually just another method of social control for the domestic population, the so called "terrorists" are not using electronic methods to communicate.