I still believe that covering your webcam is a good idea (just to be sure), but this is an interesting point:
"I have never understood the mass paranoia over laptop webcams — which have in-use indicator lights, which I’ve seen no evidence can be circumvented on Macs from the last decade — and the complete lack of similar paranoia over microphones, which cannot be blocked by a piece of tape and which have no in-use indicator lights.“