That's great if you sign up with the intention of posting anonymously, but if you post here for years using your name or your chosen alias (eg I'm onion2k on everything; it's trivial to find out who I am), and then decide you don't want to be associated with your HN history it's not so helpful. Also forensic tools are clever enough to take someone's comment history and use the little information in there to work out who you are. We leak information all over the place. A user name isn't the only way to find someone.

It's fair for people to change their mind and ask for functionality to delete data that's associated with them. I don't think the internet would be nearly as useful as it is now if everyone had to be anonymous from the start in case they want to stop other people seeing the content they created later.

However, that said, it's also reasonable to suggest people shouldn't be able to say appalling things and just delete their account later with impunity. There's a strong argument that someone's internet history should be available as a record.

This is not a straightforward problem.