Facebook's Messenger app, currently the "most popular" free app on the app store, has a one-star rating. Not only are consumers irritated by Facebook forcing them to download a separate app for sending messages, but a few clever people actually read their Terms and Conditions. Written below is a summary of the permissions of the app that you naively choose to agree upon when downloading it:
Allows the app to change the state of network connectivity.
Allows the app to call phone numbers without your intervention.
Allows the app to send SMS messages.
Allows the app to record audio at any time without your confirmation.
Allows the app to take pictures and videos with the camera at any time without your confirmation.