Lying is not a new phenomenon. Whether or not it's useful or good is a philosophical question with many answers which don't matter because if it becomes possible we will (have to) adjust and there will always be some upside if you want to see it.
Today, lying with video is really expensive, but if in the future everyone is able to do it and everyone knows that it's possible then we're back to he-said-she-said, which is how society has worked since the beginning, except the last 200-ish years. I can easily lie and say I saw Bill Clinton murder someone in 1990. Maybe in the future I'll be able to generate fake video evidence of it just as easily as I typed out that sentence. If everyone has a feel for how easy it is, then so what?
The danger is in the transition, when lying using video is affordable by a select few, and not everyone knows about it. Then it's powerful. If you're worried about that then we need to develop and teach this technology as quickly as possible. We can also do something fun like collect a time capsule of important videos before this becomes easy and timestamp it in a verifiable way (by posting the hash to a blockchain or some authority for example).
Very good post. Another factor to consider is that a technology can be powerful when everyone does know a bit about it, but the perceptions of around it can be manipulated.
To stick with your 'Bill Clinton murdered someone in 1990' example, if you are Alex Jones and you say that then I will be skeptical gien Alex Jones' serial unreliability. But if you deepfake yourself to resemble a (hypothetical) real person called Albert Johannsen who died in 1995, and manipulate the video to look like old VHS, then the authentic-seeming testimonial can be 'discovered' by someone clearing out an attic or storage unit, and then merely publicized by you-as-Alex Jones, who merely reports the claim of the discover (actually a collaborator of course).
There is an endless variety of of applications, eg you have really committed a crime and video exists, but you produce a deepfake of yourself committing the same crime multiple different ways or the like, such that everyone thinks You Did It but nobody can agree about exactly how or to what extent and you escape justice due to the ambiguity (albeit with diminished future prospects).
Today, lying with video is really expensive, but if in the future everyone is able to do it and everyone knows that it's possible then we're back to he-said-she-said, which is how society has worked since the beginning, except the last 200-ish years. I can easily lie and say I saw Bill Clinton murder someone in 1990. Maybe in the future I'll be able to generate fake video evidence of it just as easily as I typed out that sentence. If everyone has a feel for how easy it is, then so what?
The danger is in the transition, when lying using video is affordable by a select few, and not everyone knows about it. Then it's powerful. If you're worried about that then we need to develop and teach this technology as quickly as possible. We can also do something fun like collect a time capsule of important videos before this becomes easy and timestamp it in a verifiable way (by posting the hash to a blockchain or some authority for example).