Call detail records are interesting things. Besides your phone number, the number you called, and the time you started and ended your call, they contain the location of the tower that routed the call.
Yes, this does mean the NSA knows where you were. And because they can access this data "as it happens" now, they know where you are while you are calling. The accuracy of the location varies, based on a number of factors. But combine this with their storage of the call records and they know where you have been for as long as they have the historical call detail records.
It gets better...
The argument for its legality goes something like this:
From CALEA, passed in 1994 by the Republican Congress and Senate:
"The U.S. Congress passed the Communications Assistance for Law Enforcement Act (CALEA) to aid law enforcement in its effort to conduct surveillance of citizens via digital telephone networks. The Act obliges telephone companies to make it possible for law enforcement agencies to tap any phone conversations carried out over its networks, as well as making call records available. The act also stipulates that it must not be possible for a person to detect that his or her conversation is being monitored by the respective government agency."
Now this doesn't grant them blanket authority to keep track of where you've been, but it does require the telecommunications companies to grant them the access.
Once the access is in place, via equipment like this:
http://www.narus.com/
There is nothing to stop the NSA from monitoring ANY call traffic it wants, and the numbers monitored are invisible to the carrier (AT&T, etc.) while they are being monitored. So basically, the NSA can turn it on for all traffic on a SONET pipe, or even a core edge network connection at 10Gbps. We are talking about VERY BROAD ACCESS, not just international calls. This might be why Qwest and other carriers took exception. There is NO obvious means of validating numbers monitored by the carrier. The monitoring agency can see whatever they want, as it happens.
When they find something of interest, if you read the product literature at that site, they can drill down, listen real-time, record as much or as little as they want. And it isn't limited to phone calls.
So that trip you took with your girlfriend last year, yes the call home you made will show you weren't at the trade conference.
The meeting between the two execs who aren't supposed to be colluding on prices. Gee, they made calls from the same locations three times last year.
Get the idea? No basis in the law I've read for storing THIS stuff.
I'm trying to find out if the switches store, or are capable of delivering the current location data to the same call data recorders. If so, this means that while your phone is on they have a means of recording your every movement, to varying levels of accuracy, even if you aren't using the phone.
George Orwell would be impressed. And as for Bin Laden, when the fucker shows up on our soil and uses his cell phone, we'll nail his ass for sure!