[xouse]

This is one of the rare good fits for blockchain. You can get the hash of a video, or hash for each segment of a video, then store that hash in a blockchain transaction, which makes it publicly verifiable while also serving as a timestamp.

A news organization could have their own wallet that they're sending currency from which acts as a verifier that it's them, then they store a hash/s of their video on the blockchain. Then you could have a facebook/twitter player that checks the hash of shared news video clips and could display a lock icon and message that says something like this video is verified non tampered from the CNN source.