It could be the worst data breach ever -- one that reportedly resulted in the theft of the social security numbers of every American. According to a federal class-action lawsuit, the hacking group claims to have stolen personal information of nearly 3 billion people from National Public Data, a background check company. The stolen information also includes names, addresses, birth dates, and phone numbers. The hackers have reportedly released most of the data for free on an online marketplace. As more of our lives move online, our personal data like email addresses, phone numbers, birthdates and even passcodes are becoming ever more vulnerable to theft or being mistakenly exposed.