Frontend, as the word describe. At the front end of what we saw here. We can delete what we saw, but all the text are still recorded in the blockexplorer. Just like if you make a comment, you delete it. You don't see it in #esteem you don't see it anywhere anymore. But when you go to blockexplorer, which is the browser of blockchain, you will be able to find back whichever "version" you have authored, modified, or even deleted. Everything is there. Even a vote, or unvote. Which is why, the blockchain is unblockable. The only thing can be block is, not allowing it to shown in the frontend platform.