Well, I can understand the privacy issues this would cause but I work 9-5, so if law enforcement really wanted to know where I was its quite simple. Not everyone is on Pokemon so using it like batmans phone sonar device would only get a chunk of the population, let online people who uninstall it and get bored.
I believe that certain agencies have corrupt individuals and that in order to truely find out their movites and the developers , most applications should be open source. Would be great in getting peoples opinion on what uses for agencies to have all this data? Cheers for the post!