We're always happy to delete or redact identifying information. We don't want anyone to get in trouble from anything they posted to HN. We don't do it by allowing wholesale deletion of account histories, because that would gut the threads the account had participated in, which would be unfair to any commenters who replied, as well as to readers and to the community.
That doesn't mean we don't care about individual users' needs for protection—we care a lot about it, and help people with these requests every day. We just have to do so with sharper tools, and we have a big bag of tricks for taking care of these things. They include renaming accounts, retroactively assigning comments to throwaway accounts, deleting specific posts (especially if they don't have replies), redacting specific info from posts, and more.
That doesn't mean we don't care about individual users' needs for protection—we care a lot about it, and help people with these requests every day. We just have to do so with sharper tools, and we have a big bag of tricks for taking care of these things. They include renaming accounts, retroactively assigning comments to throwaway accounts, deleting specific posts (especially if they don't have replies), redacting specific info from posts, and more.