Bests & Worsts Reviews from Amazon

I don't like that I have to download this to continue to chat with my fb friends. What I really don't like is that it gives out my phone number and has me available to call at any time...people who I want to call me already have my number...why would I want everyone on fb to be able to call me!? Why is there a payment option? Is this another way for theft to occur because I'm very sure I don't want FB knowing my card info. This thing is just taking up space and it completely unnecessary....