No, No, No, No and No
And again, No, No, No, No and No.
Consider the masking tape firmly stuck over the webcam lens. It's funny, there was an advert for Microsoft (if I recall correctly) in a magazine I was reading, and it was touting the fact that the apps were "listening". My immediate reaction was "well stop it then!"
In the British political comedy series "Yes Prime Minister" there's a scene where they discuss the problems of talking in radio studio "off air", and the subsequent discovery/warning that "any microphone should be considered a "live" microphone." I would hate to think that every device in my house with a microphone or a CCD start to monitor me 24/7, and for what? It's not like it's for my own safety or anything...