Over the last seven months, we have learned an incredible amount about the government's post-9/11 surveillance efforts. But there is a crucial gap in our basic understanding. We now know, for example, a good deal about how the government conducts surveillance that targets Americans, and about surveillance of foreigners that sweeps up Americans' international communications when the actual surveillance takes place on U.S. soil (for example, from a Google facility in the United States). But we still know very little about Executive Order 12,333, which governs the NSA's surveillance abroad — even when that surveillance sweeps up Americans' communications.

To fill that gap, the ACLU, along with the Media Freedom and Information Access Clinic at Yale Law School, today filed a Freedom of Information Act lawsuit demanding that the government release basic information about its use of Executive Order 12,333 to conduct surveillance of Americans' international communications.

Why is Executive Order 12,333 so important? Here is how we explained it in our complaint (filed today in federal court in New York):

Although EO 12,333 permits the government to target foreigners abroad for surveillance, recent revelations have confirmed that the government interprets that authority to permit sweeping monitoring of Americans' international communications. How the government conducts this surveillance, and whether it appropriately accommodates the constitutional rights of American citizens and residents whose communications are intercepted in the course of that surveillance, are matters of great public significance and concern. While the government has released several documents describing the rules that govern its collection and use of Americans' international communications under statutory authorities regulating surveillance on U.S. soil, little information is publicly available regarding the rules that apply to surveillance of Americans' international calls and emails under EO 12,333. That gap in public knowledge is particularly troubling in light of recent revelations, which make clear that the NSA is collecting vast quantities of data worldwide pursuant to EO 12,333. For instance, recent news reports indicate that, relying on the executive order, the NSA is collecting: nearly 5 billion records per day on the location of cell phones, including Americans' cell phones; hundreds of millions of contact lists or address books from personal email and instant messaging accounts; and information from Google and Yahoo user accounts as that information travels between those companies' data centers located abroad.

The core of the problem is that the NSA has, for years, relied upon its authority to gather foreign intelligence as permission to conduct sweeping surveillance of Americans' international communications. We know that this happens under the laws that govern surveillance on U.S. soil, and recent revelations confirm that it happens — perhaps to an even greater extent — in the surveillance that takes place abroad under Executive Order 12,333. Moreover, the rules that govern surveillance under the executive order are of particular concern because that surveillance is not meaningfully overseen by Congress , and it is not overseen at all by the Foreign Intelligence Surveillance Court.

In other words, the executive is conducting surveillance under its own executive order without any real oversight. We now know too well that unchecked surveillance authority can lead to dangerous overreach. That's why we are fighting for the release of documents that would shed light on the internal rules that the executive has set for itself when it monitors international communications abroad — including Americans' international communications.

Stay tuned.