Yahoo confirms 500 million account details were stolen.
Here's a brief statement from Yahoo:
"We have confirmed, based on a recent investigation, that a copy of certain user account information was stolen from our network in late 2014 by what we believe is a state-sponsored actor. The account information may have included names, email addresses, telephone numbers, dates of birth, hashed passwords (the vast majority with bcrypt) and, in some cases, encrypted or unencrypted security questions and answers. The ongoing investigation suggests that stolen information did not include unprotected passwords, payment card data, or bank account information; payment card data and bank account information are not stored in the system that the investigation has found to be affected."
I have a Yahoo account, what should I do?
Yahoo have moved quickly to provide as much information as possible to their users. You can find all you need to know here: Yahoo Hack
How can I keep my passwords and data secure?
When it comes to massive, state-sponsored hacks like this, there's not much you can do. However, there are some everyday tips that can help - 5 Password Tips