The disclosure email contains the usual, and frankly by this point pretty meaningless, apologies for any 'concern or inconvenience this may cause' as well as the promises that everyone is working hard to investigate and take steps to prevent it happening again. It's worth noting that the passwords that have been compromised were encrypted and hashed with a salt that will vary from user to user. If you are a Quora user who contributed to the systems anonymously then your data will not have been impacted simply because that it does not store identity data of anonymous posters. Oh, and data that has been imported from linked networks such as contacts, demographic information, interests and (now invalidated) access tokens.
This includes names, email addresses, IP addresses, user IDs, encrypted passwords, user account settings, personalization data, public actions and content (including drafts) such as questions, answers, comments, blog posts and upvotes. While it is currently unknown how the breach happened, Quora says the intrusion was only discovered on Friday November 30th, it does know the user data that has been compromised.