There's no reason the application must always be listening. Facebook could do their voodoo to determine when during the day you are most likely to be in a socia

There's no reason the application must always be listening. Facebook could do their voodoo to determine when during the day you are most likely to be in a social atmosphere, and begin listening to the microphone only during that range of time. Processing and uploading doesn't have to happen all at once. They could analyze/process the audio while you're asleep. The power drain would be negligible - or completely unnoticeable if your phone is charging while you sleep. Data obtained from these processes could be uploaded in chunks, hidden inside the photos and videos you upload from the Facebook app. So, in my opinion, not only is this all possible, it'd be not too difficult for Facebook to hide it from the general public.