A Reddit user moved and started renting a new home. The former tenant had left behind a weird looking mirror Upon further inspection the mirror turned out to be hiding a camera:
As he investigated he found that the mirror was completely transparent, but whoever installed it covered the back with black fabric, cutting a hole out for the camera lens to fit through. There were microphones set up to capture audio as well. He doesn’t know who set up the system (though, the landlord, probably) but it’s been filming whatever has been going on in the front room of his house. He also posted proof.
So, next time you move, be sure to inspect any existing furnishings for pervy recording devices.