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Colossus: The Forbin Project also depicts an AI take-over due to instrumental convergence. But what differentiates it is the presence of two AIs, which collude with each other to take over. In fact, their discussion of their shared situation, being in control of their creators nuclear defence systems, is what leads to their decision to take over from their creators. Interestingly, the back-and-forth between the AI is extremely rapid, and involves concepts that humans would struggle to understand. Which made it impossible for its creators to realize the conspiracy that was unfolding before their eyes.
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