A bunch of people will believe it for some amount of time, and given the very low cost of producing it, it’ll be enough. If there is one thing we learned from the recent increase in mainstream extremism fueled by social networks is that fake rumors don’t have to be especially reasonable to be effective; they just need to be generated and broadcasted at a sufficient rate (selection will do the rest of the work). One interesting question is: is one protected by freedom of speech when generating fake videos clearly intended to harm another person’s image?
I dunno, I don’t think people need to be tricked into thinking certain things. It’s usually what they want. I don’t think promoting “the facts” or worrying about fake videos is going to change anything directionally.
