The prospect of human-killing robots walking among us on our streets is a very scary one, and while it was once stuck firmly in the realms of science fiction, it is now becoming a distinct possibility. It’s no wonder, then, that thousands of scientists and artificial intelligence researchers signed an open letter calling for them to be banned in July this year. Lethal autonomous weapons systems, as these killer robots are known scientifically, are being made and tested by several hi-tech nations such as US, UK, China, Russia, Israel and the Republic of Korea. They look like futuristic fighter jets, tanks, ships and submarines, and they can be sent to find targets and kill them without human supervision. But this is a bad idea. No one can guarantee that these weapons will comply with the international laws governing conflict, and there are far too many circumstances in which a machine would not be able to tell the difference between a civilian and a combatant, especially in the fog of war.