Can your webcam be used to spy on you?

[DioneTheDiabolist]

I used FaceTime to contact someone earlier. When they answered I could hear them, but the screen was black. When I mentioned it they told me they covered their webcam with tape so no one could see them when they weren't looking (and removed the tape).

I was . Can your webcam be used remotely to spy?

I googled it and it appears to be true.