Speed limit enforced by AIRCRAFT

Expanding a bit on a comment I made to Kevin Drum: if the SWIFT program was losing its effectiveness ("The bad guys figured out how we were catching them."), then the logical thing for the government to do was to bring the program out into the open. Sometimes the police run speed traps, but other times they just put up big signs that say, "we're watching you" and hope that will deter people from speeding. Of course, it's even more effective if the warning comes from someone else. Most people ignore those signs, but slow right down if an oncoming car flashes its lights.

To use another analogy: if you find a rat hole, you might want to put traps around it. But eventually the rats will get wise to the traps, and then the best thing to do is to plug the hole. In the NSA's case, the best way to plug the hole (terrorists using foreign banks to transfer funds) would be to leak the fact that they are monitoring the transactions.