bitcoin can already provide proof of existence in a similar way if that is the key advantage expressed, if they claim to be able to store an indefinite amount of future data instead, as could be inferred by a quick scanning of the text, I find it very hardly scalable at all, there could be useful files of any size passing through the voting system and the blockchain should be replicated by each client on the network in theory in order to safeguard the network from possible missing nodes