An apprentice says a breaker will protect people from electric shock because it trips on overcurrent. What is wrong with that idea?

1. 1Breakers respond only to voltage changes and never to current, so they cannot help.
2. 2Shock happens at currents far below the trip point.
3. 3Breakers work only on DC circuits, so they do nothing on a normal AC supply.
4. 4Overcurrent devices are tested for open circuits only, never for shock.