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Do you hear that? It's starting.

The predictable drumbeat of dire warnings about what will happen if portions of the Patriot Act – the post-9/11 law being used to conduct controversial NSA dragnet surveillance – are allowed to expire on June 1 has already begun.

James Clapper, the director of national intelligence, issued what is likely to be the first of many vague warnings from the intelligence community . Faced with the expiration of the part of the Patriot Act that allows the bulk collection of information about Americans' phone calls, Clapper brought out the favored hypothetical of the surveillance hawk: An unspecified attack will occur, which would have been prevented if Congress had reauthorized the dragnet collection of Americans' phone calls.

"If that tool is taken away from us... and some untoward incident happens that could have been thwarted if we had had it," Clapper said, "I hope that everyone involved in that decision assumes the responsibility."

There's just one problem with this particular bit of emotional blackmail, however. The pesky, rather inconvenient fact is that the government's mass surveillance programs operating under Section 215 of the Patriot Act have never stopped an act of terrorism. That is not the opinion of the NSA's most ardent critics, but rather the findings of the president's own and the . This program has had over a decade to prove its value, and yet there is no evidence that it has helped identify a terrorism suspect or "."

In less than three months, Section 215 will expire unless Congress takes action to extend that authority. As that deadline approaches, we will be hearing more from folks in the intelligence community who would like to see the program continued indefinitely.

Congress would do well to remember that this is a program that is sweeping up vast amounts of data on innocent Americans in violation of their constitutional rights. It's also one that, despite the rhetoric, has not succeeded in making us any safer. In fact, even Director Clapper has for some reform of Section 215.

The drumbeat of doom is only going to get louder between now and June. But it can't drown out the truth. Surveillance reform is urgently needed to rein in out of control government spying and to restore our rights.

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