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 thing with cell phone calls and e-mail Internet routing information. It wants to know who the terrorists are communicating with in order to paint a picture of their organization. To listen to a phone conversation or read e-mail text, the agency must get FISA court approval and needs justification in order to do so.
Remember when the military killed Osama bin Laden and captured his thumb drives? The military probably got cell phone numbers and e-mail addresses aplenty. The information on the thumb drives probably was used for FISA court justifications for specific cases of investigation.
We won the Battle of Midway in 1942, but will we win the terrorist battles to come by not allowing the NSA to perform traffic analysis?