In the past year there have been many major data breach incidents in which usernames, email addresses and sometimes even passwords were compromised. Some of these incidents included big organizations with millions of usernames leaked.
According to the 2014 Trustwave Global Security Report, “The volume of data breach investigations increased 54 percent over 2012” and “45 percent of data thefts involved non-payment card data”.
In my personal blog I wrote a post describing how I obtained the ability to extract email addresses hosted on Google's email service Gmail, including email addresses belonging to corporates that externalized their email management through Google Apps for Business.
After reading my blog post people questioned how important email addresses and usernames really are. “Why is it such a big deal when email addresses or usernames are stolen?” is a question I get asked fairly frequently. This post will attempt to answer that question.