The Yahoo data breach keeps getting nastier. The company has now said that every single account was affected by a data breach that took place in 2013. That means all 3 billion user accounts. It is important to note that, in connection with Yahoo's December 2016 announcement of the August 2013 theft, Yahoo took action to protect all accounts. The company required all users who had not changed their passwords since the time of the theft to do so. Yahoo also invalidated unencrypted security questions and answers so they cannot be used to access an account The news comes as Yahoo was being integrated with Verizon, which bought the company in June for $4.5 billion.