just found an interesting and serious bug in MS Teams. When in meeting, there was someone joining from Android phone (I think). Despite him having his camera off, I was still able to see him by quickly vertically resizing meeting call window. When resizing an element with his video stream briefly showed up. This was also possible to do by other participants.
Those camera protectors can actually help in your everyday.
Edit: when coworker came onsite we talked about that and he told us that he enabled camera by mistake for a brief moment and that what we were seeing was probably just a frame from that stream. So yeah, the thing is not so broken anyway :)