I think you mean https://en.wikipedia.org/wiki/Keybase https://en.wikipedia.org/wiki/Keybase ? Some years ago there was a wave of new user accounts, all putting

I think you mean https://en.wikipedia.org/wiki/Keybase https://en.wikipedia.org/wiki/Keybase ? Some years ago there was a wave of new user accounts, all putting their keybase identity string (long hash) into their HN profile. Turned out some crypto coin used keybase to limit the number of users to receive 'drops' (free coins). So anonymous users created anonymous HN accounts (probably with anonymous email addresses) and once they had 3 accounts connected they were able to get free currency.