Last week the email marketing company Epsilon announced it had suffered a security breach that exposed an as-yet unknown number of personal email addresses to hackers. While Epislon and many of its affected clients - including Capital One, US Bank, LL Bean Visa Card, Citi, and JP Morgan Chase - were quick to reassure customers that the hackers gained no other sensitive information such as credit card numbers, this breach could still have big repercussions on anyone in the recurring-billing and o...