The word “spying” should be replaced with “traffic analysis.” The National Security Agency is performing traffic analysis like before the Battle of Midway during World War II.
In 1941, the military wasn’t able to decipher the Japanese messages but could read the “To,” “From” and “Copy to” lines of messages. This information was married with location information derived by multiple direction findings from Alaska to the Panama Channel. A Navy officer put these pieces of information together into a picture of the Japanese fleet structure and the various task force movements about the Pacific.
The NSA is doing the same …