In the data drawn from apps, each cellphone is typically represented by an alphanumeric identifier that isn’t linked to the name of the cellphone’s owner. But the movement patterns of a phone over time can allow analysts to deduce its ownership—for example, where the phone is located during the evenings and overnight is likely where the phone-owner lives.

Source: U.S. Government Contractor Embedded Software in Apps to Track Phones – WSJ

By EdwardM