This document is an attempt to debunk all of those "Facebook Messenger is evil!" messages that are cluttering up my news feed. There's several versions of it, but this document is using this one for separating each claim: http://threepercenternation.com/2014/08/facebook-crosses-the-line-with-messenger-app/
Please let me know if I missed something or got something wrong - and if you're interested in working on an Android/Windows Phone version of this then that would be swell too!
Call phone numbers and send SMS messages – This means that if Facebook wants to…it can send text messages to your contacts on your behalf.
Developers can create a link that contains a phone number (tel:// URL Scheme), but the user will always be prompted with a "Call" action button - no phone call can automatically be triggered.