Bioweapons and cyber attacks on other system - for example the banking system or suppose and AI hacked into important Russian systems that pushed them back in time to almost pre-computer society or an attack on Chinese systems that made it look like the US was moving nuclear weapons into Taiwan, the responses from these countries could be awful and dramatic. We can't control what they do to be honest, I believe once self improvement happens the AIs will build in their own circumvention that we humans cannot even understand. We barely understand what is happening now in terms of interpretability of neural networks on tiny problems I'm not sure alignment is even feasible at the scales of parameters we are talking about today let alone in the future.