The company said that not all users were affected and that "some were impacted more than others".
You've probably already received an email from Quora if your data was compromised.
For about 327 million of the total 500 million affected, the compromised information included data such as names, mailing addresses, phone numbers, email addresses, passport numbers, Starwood Preferred Guest account information, date of birth, gender, arrival and departure information, reservation date and communication preferences.
"Public content and actions, e.g. questions, answers, comments, upvotes [as well as] non-public content and actions, e.g. answer requests, downvotes, direct messages".
Quora has started notifying users whose data has been compromised, and will log them out of the site "out of an abundance of caution".
"Once the 14-day grace period has expired and your account has been deleted, your content and profile will be permanently deleted, and personal data associated with your account will be removed from Quora's databases", says the company on its website.
Basically anything that wasn't done anonymously on the site was compromised. The site will ask you to enter your password to confirm the deletion of the account.
If your Quora password was the same as your Google or Facebook password, you should change that too.
To disconnect your linked accounts go to your profile picture settings account and scroll down for connected accounts.
What is Quora doing about it?
"We are working rapidly to investigate the situation further and take the appropriate steps to prevent such incidents in the future".
D'Angelo said the company is notifying users who may have been affected by the breach and invalidating their account password as a precaution.