As you can imagine, giving an application access to your exact location is quite a big deal. In the wrong hands, this data could allow people with malicious intentions to know exactly where you are at any given time, and abuse this knowledge in many different ways. For this reason, it's essential that you only request a user's location if you absolutely have to. Simply using it for a small feature, or to make sure a user is in some arbitrary location before they sign up for a service, might not always be a good enough reason to ask for a user's location.