I suppose you could have 'trusted devices' where upon taking pictures/videos a hash of the file is committed to blockchain. Although a privacy nightmare. This

I suppose you could have 'trusted devices' where upon taking pictures/videos a hash of the file is committed to blockchain. Although a privacy nightmare. This obviously wouldn't solve the 'no fake videos' problem but would least mean 'this video isn't fake' for a select subset. There could be tiers of information in the future where this audited media is weighted higher.