Here is a MAJOR security problem: If you’re an iPhone user and have installed Pokemon GO, you may have noticed that the app grants itself full access to your Google account. It can read your email, location history, documents and pretty much every else associated with your Google account.
If you use Gmail, Pokemon Go can read it and forward it to anyplace the programmers please. Pokemon Go can also track all the movements of your iPhone and see where you have been.
Details may be found at https://goo.gl/YcCSqB.
Do you REALLY want that game installed?