I remember seeing examples from conflicts where video from another event was passed off by the mainstream media to spin the story. It was not until it was called out because people found the real source and posted it debunking what was shown.
I expect more or less the same process with deep fakes. Find the source material and then show how it was adulterated to produce the fake.
I'd be far more terrified if there were an AI capable of generating genuinely catchy/hilarious/original meme images. The "original" part is the hardest part of the equation, because even if you managed the "catchy/hilarious" part (which is already almost impossible), the novelty of the results would wear off quickly if the machine isn't capable of true originality.