Apple is telling it’s customers to disable FaceTime.  It seems that there’s a glitch and someone could be secretly listening to you.  The bug lets a user listen in on people they’re calling, even if the person doesn’t answer the phone.  
To disable FaceTime on your iPhone, iPad, or Mac, follow these steps.

Disabling FaceTime on a Mac:
–Open the FaceTime app
–Choose FaceTime in the menu
–Choose “Turn off FaceTime”

Disabling FaceTime on an iPhone or iPad:
–Open Settings
–Scroll down to FaceTime app
–Hit the button, turning green slider to gray