The U.S. National Security Agency's mission is to gather information about foreign terrorists and foreign powers, not to carry out wholesale domestic surveillance.
Apparently, however, its technical capabilities have outrun all existing legal constraints. It is routinely vacuuming up data about the communications of all Americans and copying information flowing from servers run by giant American online companies.
The NSA, now constructing a massive $2 billion data-storage facility just outside Salt Lake City that will presumably be capable of chewing through everything each of us says, needs to be newly reined in. After all, the most valuable intelligence is information from people everywhere, and we have access to that gold mine only if the U.S. remains a beacon to the world.