Of course, any AI that is sufficiently advanced to sway both public and personal opinion will probably also be able to mount a 51% attack against whatever blockchain we expect to refute its lies.
Not so: 1) because the abilities of AI don't scale in that manner and 2) because, unlike in a true decentralized blockchain, there are centralized trust sources that you can use to verify the content. This is really a better use case for keybase rather than blockchain.
