The cognitive dissonance of thinking that apps are needed to track someone with a phone vs just being able to track your phone directly is very telling. Even before smart phones with apps, the tracking was there as a required feature to make mobile work. Granted, the number of people that spend any cycles thinking about how mobile signals work probably rounds to 0. It takes someone really dialed in to the details to come up interesting bolt on things to an existing system like tracking people with a mobile device just by looking at the logs. Same thing with looking at "just the metadata". While it may be obvious to those dialed in, to those oblivious it sounds crazy.