Why the “Secret Law” of the Patriot Act Is Probably About Location Tracking

Reads various tea leaves to make a case that the NSA is blanket recording location data, which is necessary for a particular highly desirable use case, specifically:

You have suspect A on your radar and he only communicates with B, C, and D face to face. Phone call metadata won't likely help, certainly not directly. Location data will only help you if you can match it against a very large data set including B, C and D's movements.