That still leaves the other problem - people will eventually stop believing real video evidence. Cops will claim videos of their abuse are deepfakes, and people will believe them. Politicians will claim that recordings of them soliciting bribes are deepfakes, and they'll be off the hook. Concrete evidence of misdeeds is one of our best ways to hold powerful people accountable, but with deepfakes they can simply flood the web with fake incriminating evidence and we'll become so accustomed to ignoring it that we ignore real evidence as well.