The rumor of the week was that Yahoo had been hacked and they were getting ready to confirm it, the numbers being floated around were ~300 million users would be affected. Apparently the breach was worse than expected as Yahoo confirmed that they lost 500 million accounts information and it all happened in late 2014. User information was stolen, however, it appears that financial data was not taken. I'm pretty sure Yahoo isn't very happy about making headlines for this as they are in the process of getting bought out by Verizon. CNN Money has the full story.
The company said it believes a "state-sponsored actor" was behind the data breach, meaning an individual acting on behalf of a government. The breach is said to have occurred in late 2014.
"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," Yahoo said in a statement.