Colossus: The Forbin Project (1970) [View all]
https://archive.org/details/colossus-the-forbin-project-1970
The US has built an AI system with the goal of ending war. They have put the security of the country under the control of this AI called "Colossus." Colossus quickly discovers that "there's another," meaning another AI system, built by the USSR. These two agents then hook up, share all their knowledge, and develop their own new language that humans cannot understand. Now the entire world is under the control of this AI.
The rest of the film shows the attempts of man to wrest control back from Colossus.
Pretty much the only thing that looks different from today is the form-factor of the technology. I encourage everyone to view this (streams free at the Internet Archive). Aside from the overall message, it was refreshing to travel back to that era and see mid-century aesthetic (notwithstanding the blatant sexism...). The film itself barely uses any musical score, or at least I hardly noticed one--also nicely refreshing.
Go watch it and come back and let's discuss it. It could hardly be more relevent today.