[ryandrake]

You'd be surprised how much you could piece together with obfuscated (but still unique) usernames. I'd be in favor of your system if the hash was salted with the article's id, so that the hash of my username in one article was different than the hash of my username in a different article.

One day I'm going to run for office and I'm going to have to get lawyers to scrub HN of all my comments because they have no way for users to manage their content :-)

[krapp]

Really, usernames only have to be unique within a single thread, don't they?

You could get away with something as simple as incremental ids in that case - user1, user2, etc.

[kctess5]

Yeah that was my reasoning. The salted hash would be an easy way to implement single-thread username consistency.

Edit: for better readability it could be further mapped into a table of human readable handles, similar to how Google does the "Anonymous Lemur" thing in gDocs.