They just had a thing on the news last night saying to avoid it because it runs at all times on your phone and sending people's data usage through the roof and costing them tons of money! The way I understand it is that Facebook messenger can access your camera and stuff when the app is running. Could they in theory write some sort of code or program to turn on these devices whenever they want... I don't see why not. But would they? I don't know. I just don't use it or social media period. I have enough drama in my personal life already.