Nearly Fired
I had a friend who was a special ed teacher. He was playing the harmonica and briefly turned his back to the computer while online. A student had turned down the volume on his computer and thought my friend was simulating something completely inappropriate. So, the student recorded a brief clip of an inopportune moment and almost got him fired for inappropriate behavior and harassment of a minor. There was an investigation, and he was cleared, but it was pretty traumatic.
Story credit: Reddit / LeeSheltonsHat