Inventions often arise from the misuse of technology. Best proof of this is Blocksign, a website and service for cryptographically signing any legal document, contract, or agreement with a technology that was originally invented to transfer money.
The purpose of the Bitcoin blockchain is to store monetary transactions in a way that it is tamper proof. Blocksign uses the "comment" field of bitcoin transactions while sending money to itself to stores cryptographic signatures of legal contracts. Once a signature is stored this way, it gets replicated by the monetary system to tens of thousands of computers across the world and becomes virtually unremovable by any entity. After all there is no decision, law or even a war that can remove a blocksign signature from the internet.