Pokemon Go uses and stores GPS location data, and users must agree that the Pokemon Company reserves the right to share this information with third parties. But that’s not all. Not only can the user’s device be located generally or precisely, but the app obviously accesses the camera and not so obviously accesses the user’s storage, contacts, and network connections, among other things.
Users logging in through Google also automatically grant access to their Gmail, Google Docs, and other Google applications. Niantic can basically use this outrageous amount of data in any way they see fit, and if they have specific plans for it, they’re not saying.
Of course, the information collected and Niantic’s free use of it is all spelled out in the License Agreement, which explicitly states that location data may be provided to law enforcement if the need arises. But it gives few other specifics. Speculatively, it seems obvious that the marketing opportunities which could arise from legally tracking the precise movements of millions of people at all times are potentially tremendous, to say the least.