It's more than possible, it's happening. There are wikileaks files stored in the blockchain. Pictures of Nelson Mandela, etc. Most people put messages/articles in the blockchain for proof, and to be time stamped. Others put things in the blockchain for public access. Another point of putting something in the blockchain is that it can't be removed. So, if you are a writer in a highly censored country, if you put something in the blockchain, the government can't remove it. Although, the writer may still get punished, the content can't be removed. And other miscellaneous reasons drive people to put things in the blockchain.