Extreme corner case for autonomous cars — giants riding on cars down hills!
So, imagine you are driving along in your fancy high-tech car, minding your own business, with your yet-to-be-feature-complete full self-driving software activated, and suddenly the car slams the brakes to a full stop, like a donkey that had an epiphany that what it was doing just didn’t serve any purpose and therefor just refused to move any further. The silicon brain of your clever-as-a-donkey-robo-car just slammed on the brakes because it saw this through one of its cameras.