“It’s a single point in the system through which all of the content can be collected if they can manage to activate it,” said Edward W. Felten, a computer science professor at Princeton and one of the authors of the report... “That’s a security vulnerability waiting to happen, as if we needed more,” he said.

Two decades ago, the FBI complained it was having trouble tapping the then-latest cellphones and digital telephone switches. After extensive FBI lobbying, Congress passed the Communications Assistance for Law Enforcement Act (CALEA) in 1994, mandating that all telephone switches include FBI-approved wiretapping capabilities.

CALEA was justifiably controversial, not least because its requirement for “backdoors” across our communications infrastructure seemed like a security nightmare: How could we keep criminals and foreign spies from exploiting weaknesses in the new wiretapping features? Would we even be able to detect them when they did?

Those fears were soon borne out. In 2004, a mysterious someone — the case was never solved — hacked the wiretap backdoors of a Greek cellular switch to listen in on senior government officials … including the prime minister.

Think this could only happen abroad? Some years ago, the U.S. National Security Agency discovered that every telephone switch for sale to the Department of Defense had security vulnerabilities in their mandated wiretap implementations. Every. Single. One.

“We’re getting to a gap between what the public thinks the law says and what the American government secretly thinks the law says."

As members of the Senate Intelligence Committee we have been provided with the executive branch's classified interpretation of those provisions and can tell you that we believe there is a significant discrepancy between what most people - including many Members of Congress - think the Patriot Act allows the government to do and what government officials secretly believe the Patriot Act allows them to do.

Legal scholars, law professors, advocacy groups, and the Congressional Research Service have all written interpretations of the Patriot Act and Americans can read any of these interpretations and decide whether they support or agree with them. But by far the most important interpretation of what the law means is the official interpretation used by the U.S. government and this interpretation is - stunningly -classified.

What does this mean? It means that Congress and the public are prevented from having an informed, open debate on the Patriot Act because the official meaning of the law itself is secret. Most members of Congress have not even seen the secret legal interpretations that the executive branch is currently relying on and do not have any staff who are cleared to read them. Even if these members come down to the Intelligence Committee and read these interpretations themselves, they cannot openly debate them on the floor without violating classification rules.

The deal between Senate Majority Leader Harry Reid and House Speaker John Boehner calls for a vote before May 27, when parts of the current act expire, according to officials in both parties who spoke on condition of anonymity. The idea is to pass the extension with as little debate as possible to avoid a protracted and familiar argument over the expanded power the law gives to the government.

"Specifically, these businesses would be substantially harmed if their customers knew that they were furnishing information to the FBI. The stigma of working with the FBI would cause customers to cancel the companies' services and file civil actions to prevent further disclosure of subscriber info."