Extreme surveillance and censorship of the internet, especially if it comes to mandates of ISP level filtering. AI-powered disinformation by the governments. IMF requiring ban on Bitcoin from member countries maybe (you probably know way more than me about the power dynamics etc. regarding that. If it could happen, Bitcoin would of course still work (except where and if blocked by the ISPs of said countries, maybe - even if I know a bit about networks, I'm no expert), but I would assume the value would fall drastically due to the severely reduced market).

While none of these things are lethal in themselves, second order effects will be - police violence, suicides, etc. and if considering opportunity cost-type effects, deaths that could have been prevented by the advancement of society.