When I rode the school bus, back in the 90's, all the busses had a prominent box for a camera. We were told that even though cameras were super expensive, the school district had two and they moved them to different busses all the time. So you better behave because there was a 2/7 chance that you were on camera. I don't know how true that was, because it was a K-12 bus and there were all sorts of schnagans going on.