According to our over paid IT guy,
You have to cut the power to it, use a power strip or simply unplug it.
Same with computers that are ten years old or newer.
Laptops have batteries so you would have to drain the battery all the way or remove it.
Apparently, many light sensors on devices are actually functional cameras and they were able to hack those as well. So even a TV with no camera feature could be used to get video.