14-year-old Grant Thompson was getting ready to play video games with his friends when he stumbled upon an alarming glitch in Apple's Facetime feature.

That confusion turned out to be a major bug in Apple's group FaceTime software which allowed iPhone users to hear audio from the recipient's phone even if that person had not yet picked up the call.

Apple says it is aware of the problem and will issue a software patch later this week to fix the bug.

Until then, users are being told to disable FaceTime until the fix is made.