The old Logitech webcam I use at work has a shutter you can close to be sure of privacy. You cannot know if the microphone is active. I don't have a cover on my home webcam, but I could point it away from me. I expect we will see more attacks like this.
I've heard plenty about people hacking into baby monitors and standalone cameras. Those tend to have weak security. That makes them easy to use, but people will not be aware of the dangers.