http://www.techradar.com/news/yahoo-now-claims-all-3-billion-accounts-were-affected-in-2013-data-breach

Remember the news about the big Yahoo data breach last year? More importantly, remember wondering if your data was affected? As it turns out, yes, merely having an account back then meant your information ended up in the hands of the perpetrators.

Back then, Yahoo thought “only” 1 billion people were affected (up from initial reports of 500 million). But today the beleaguered company released a disclosure notice to the U.S. Securities and Exchange Commission (SEC) reporting the discovery of new evidence proving that the breach extended to every one of the 3 billion accounts registered at the time.