It all comes down to identity. One simple solution in theory is to only look at videos that come from a reputable brand like BBC, NBC, etc. AND going directly to their site. But of course that isn’t going to happen in mass. But probably the best solution is to have a law requiring social media companies to clearly show the origin of the videos via digital signatures (or prominently display if they are unverified), but that requires a wisdom and motivation that Congress just doesn’t have. (I wrote a recent Medium post in the topic).