Someone is trying to steal archive.is's domain

You're also right that there is a huge cost to creating a secure blockchain from scratch, but the incremental cost of using an already secure public blockchain (such as Ethereum's) can be lower than the amount of value it brings to the table.

Proving the existence of data, at specific timestamps in the past, when keys may have later been compromised, does seem like a use case that requires tamper-proof distributed consensus between untrusted parties. Whether that use case is particularly valuable or not is harder to judge, though, I admit.

Just because my SSN got leaked to a few people doesn't mean it needs to be leaked to the world. Most people aren't going to take advantage of my SSN, so having it leaked to a few arbitrary people is a relatively minor risk. And if it does get abused, there's a very small pool of suspects. Having my SSN get publicly broadcast to the world pretty much guarantees I'll be plagued by identity theft forever and gives me no suspects when it happens.

Same goes for plenty of other private information. Just because it's leaked to some people doesn't remotely justify giving it to the whole world.

> The reason to preserve and re-publish something that was once known, is so that no single party gets to use it, or use it's absense, against everyone else.

We're not talking about secret cheat codes that give the owner power over everyone else. We're talking about private information. If a "single party" has my private information, they have power over me, but that doesn't give them power over anyone else. In this scenario your argument seems to be "if one person has power over me, that's unfair to everyone else who doesn't, so they should be given the same power over me as well", which is of course complete nonsense.

I don't understand this argument. If, say, my credit card information is published, it can only be used to harm me. Removing it causes no harm to anyone else, so leaving it published _only_ causes more harm.