Comment by uptown

On a separate matter, how does Facebook Paper get its permissions? I have the Facebook app installed on my iPhone, but I don't have Facebook linked to the operating system. When I installed Paper, I was never prompted to login. Are they able to read a piece of information shared by the normal Facebook app in order to authenticate Paper users without requiring an additional login? Doesn't that violate the sandboxing of application data, or are they able to circumvent those policies since it's all associated with the same app publisher?