One way is a proof of existence direction: you create a Hash about your file or document and store it in the blockchain with some owner or right information. However, the topic is not a pure blockchain one, like if you consider for instance videos, it is not so simple to create a hash, because the same video might exist with different quality resulting different file stream to hash.

    Here is link on a symposium about the topic:
    www.ivir.nl/blockchain-copyright-symposium/