(W)Archives: Incidental Collection

July 11, 2014
WWII Intercept

We’ve heard a lot about “incidental collection” recently. This is intelligence jargon for “we collected information we didn’t really care about while trying to collect something else.” As Joshua Rovner pointed out in his recent and outstanding piece here at War on the Rocks, “the technical details of signals intelligence are stupefying, but the fundamental problem is not. Most of what intelligence agencies collect is irrelevant, and the basic task of intelligence analysis is to determine the difference. NSA analysts don’t like noise and try to avoid it.”

Privacy advocates are, of course, concerned about the interception of communications data involving Americans. This problem is compounded by the massive growth in data transmissions in recent years. A more fundamental problem is that many of the intelligence targets today, particularly terrorists, use the same communications channels as the rest of us.

However, incidental collection has always been a problem, even in the good old days when targets or collection typically used special communications channels. See, for instance, today’s (W)Archives document. It contains two side-by-side historical pieces drawn from David Kahn’s outstanding book, Hitler’s Spies: German Intelligence in World War II, where they are reproduced in facsimile. The first item is an absolutely banal, one-page State Department cable dated December 1944, assigning someone to be Economic Counselor in the United States’ mission to the Polish government in exile and discussing this officer’s per diem and travel orders. One of the German signals intelligence services intercepted this document and translated it to German. Because of the sensitive methods by which it had been acquired and decrypted, the service classified it Geheime Kommandosache, the equivalent of TOP SECRET. You can be sure that the officer who decrypted this item rolled his eyes in chagrin over the time he had wasted after seeing the translation. Of course, the problem goes even farther back. During World War I, U.S. Army officers were known to criticize American Expeditionary Forces signals intelligence organization, G-2-A-6, for wasting time decrypting worthless intercepted German messages.

Reasonable debates can be had—should be had—about how aggressively NSA and other intelligence agencies should collect and how long they should retain useless material. But we should have this debate in full knowledge that the problem of incidental collection can never be solved.


Mark Stout is a Senior Editor at War on the Rocks. He is the Director of the MA Program in Global Security Studies at Johns Hopkins University’s School of Arts and Sciences in Washington, D.C.


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