For a few years I have been predicting the advent of a kind of cognitive weapon of mass destruction, a "propaganda doomsday weapon."

This would be a dishonest/manipulative debate AI paired with big data and microtargeting. It's like pairing a trained and primed con artist with every single human being in parallel and having it shadow and work on them 24/7. Big data and cross agent "fleet wide learning" would allow it to get smarter very rapidly.

I consider this scenario to be as much of an existential threat as atomic and biological weapons.