See this FLI page for more details
"Lethal autonomous weapons systems can identify, target and kill without human input, according to the Future of Life Institute, a Boston-based charity that organized the pledge and seeks to reduce risks posed by AI. The organization claims autonomous weapons systems do not include drones, which rely on human pilots and decision-makers to operate.
According to Human Rights Watch, autonomous weapons systems are being developed in many nations around the world — “particularly the United States, China, Israel, South Korea, Russia and the United Kingdom.” FLI claims autonomous weapons systems will be at risk for hacking and likely to end up on the black market. The organization argues the systems should be subject to the same sort of international bans as biological and chemical weapons.
FLI has even coined a name for these weapons systems — “slaughterbots.”"Tech leaders: Killer robots would be ‘dangerously destabilizing’ force in the world -- The Washington Post