For example: You find a security vulnerability in some applications. You want to make an anonymous disclosure but you want to be able to prove you knew about i

For example: You find a security vulnerability in some applications. You want to make an anonymous disclosure but you want to be able to prove you knew about it at a certain time. So you create the message "I John Doe has found the vulnerability ..." and add the hash to the blockchain. You can now definitely prove that you knew about it and had documented it at a certain timestamp before the disclosure.