As you may have heard, there is a flaw on Apple Facetime for iOS and Mac that makes it possible for someone to listen in on what the microphone of another user hears even if that person hasn’t accepted the call.
It only happens if you add someone to a group conversation and Apple has temporarily disabled Group Facetime to prevent it from being exploited. However, in an abundance of caution you can also disable Facetime:
On iOS (iPhone and iPad)
Click on Settings
Scroll down till you see Facetime and click.
Toggle off the green button on top
Open the Facetime App
Click on Facetime on top of the screen
Select “Turn off Facetime.”