Streaming on line for parents’ benefit.
Yes. Just as testing in manufacturing is not done on every widget and accounting audits do not check every number, random sampling could be very effective. Never knowing when someone might be watching could put teachers on their best behavior. No employee has any expectation of privacy while at their workstation, right ?
There were microphones in every classroom when I was in school, but the teachers knew the only person who could even possibly monitor it was the principal so it wasn’t very effective. Knowing parents might check in at random would be a different story.