[lokedhs]

So if someone uploads a 2 hour version of a rickroll and tags it with the name of the latest blockbuster movie and then takes it offline, there is now going to be a permanent record that at some time there was a copy of this movie uploaded? When in fact that never happened?

How is this in any way better, or even something beneficial?

[hirundo]

Tamper evidence. The blockchain link would include a hash of the contents, making it impractical to modify rather than disappear content.

[lokedhs]

Sure. It will contain the hash of the rickroll video. That doesn't help with the question as to who proves that the content is what it claims to be?