OFF WITH THEIR HEADS!
"hack by an unauthorized third party in August of 2013" The comments above seem to neglect the fact that the hack was more than 3 years ago and was discovered in November of this year when "the hack was discovered after law enforcement officials provided the company with what appeared to be Yahoo user data from an unknown source."
If you as a Yahoo mail user changed your password, as suggested, within the past year, you should not have to worry about someone using your info … although you should still expect the scam emails from Mexico, Romania, Tel Aviv, Pakistan, Venezuela, Morocco, Russia, Germany, UK, China, Vietnam, Tunisia, Brazil, Latvia, and, of course, Nigeria.
Opening a Gmail account will provide you with other sources of spam as the Gmail is scanned for key words and ads will pop up based on those key words.