Pokemon Go is owned by Niantic, which is a company under contract with the NSA to provide geospatial intelligence data.

Essentially when you "find pokemon" and take a picture, you're helping intelligence gathering by providing a photograph of missing 3d data. You're helping create a 3d model of every building, inside and out, every street, alley, book and cranny of every city, road, forest, etc across the globe for the US government.