Should Your Driverless Car Kill You to Save Two Other People?

There's a train speeding down the tracks towards five innocent people who will never get away in time. You can save them by pulling a switch, but it'll kill another, different person on a different track. Do you do it? It's a thought experiment people have debated for ages, but it's about to become a real dilemma when we program robots to pull the switch, or not.