Current smartphone platforms provide ways for users to control
access to information about their location. For instance,
on the iPhone, when an application requests access to location
information, the operating system asks the user whether
to grant location access to this application. In this paper, we
study how users are using these controls. Do iPhone users
allow applications to access their location? Do their decisions
differ from application to application? Can we predict
how a user will respond for a particular application, given
their past responses for other applications?