Hello, I noticed that many apps require the user to login via Facebook, email account or sign up for a new account. What is the reason for doing this? For example, I installed an app called Fyuse. When I launched it, it asked for login to Facebook, Twitter or sign up for mail address, creation of account. I recall that when I launched Instagram, it asked me to connect to connect it to Facebook, or create a new account. After installing pocket, it asked me to register via google or email address. It seems that Facebook is some kind of big brother. If whenever an app asks me to connect to FB, I give FB access to too many information.