You would think people like Comey would consider this a necessary security measure.
For instance, it could provide an alibi if something was done via your computer and the video evidence shows you weren't using it at the time, or that someone else was.
Yeah, good point. But the same thing could be said for my job, where I have access to sensitive patient information. I still cover the webcam. I make sure I lock my computer whenever I’m not sitting in front of it, and I don’t need the webcam for anything. So I see it more as an intrusion than a potential alibi.