Yahoo says hackers stole data from 500 million accounts in 2014

Yahoo Inc said on Thursday that at least 500 million of its accounts were hacked in 2014 by what it believed was a state-sponsored actor, a theft that appeared to be the world's biggest known cyber breach by far.

Cyber thieves may have stolen names, email addresses, telephone numbers, dates of birth and encrypted passwords, the company said. But unprotected passwords, payment card data and bank account information did not appear to have been compromised, signaling that some of the most valuable user data was not taken.