In September, Yahoo revealed a 2014 security breach that involved 500,000 of its users’ accounts. Now the company has announced an even larger data breach from 2013 involving more than one billion accounts, including those of more than 150,000 government and military employees. “The two attacks are the largest known security breaches of one company’s computer network,” reports The New York Times. “The newly disclosed 2013 attack involved sensitive user information, including names, telephone numbers, dates of birth, encrypted passwords and unencrypted security questions that could be used to reset a password.”