Sure, but in this end of the world, machine domination, and terminator like scenario, they still need to convince us to use a webcam and a mic on the computer.
1) They grabbed these images just to test their image recognition.
2) Earlier leaks have already shown that cameras and microphones can be accessed without user knowledge, and earlier defects in products show that the light does not always come on for cameras.
You're imagining that they will ask for consent. They will not. You are equipping yourself with a lot of sensors in a network connected device, and to this they simply say "Thank you". Or would, except they're not going to say anything.
