If you are not familiar with www.social-engineer.org, I strongly recommend it as a great source of information regarding all aspects of social engineering. Why is this important? In their own words:

Social engineering is a real and dangerous threat to Corporate America. In the simplest of terms, social engineering is manipulating a target to take an action that may or may not be in their best interest. As companies devote more resources to technical security, technical attacks become more expensive. Social engineering is a popular alternative for cyber criminals interested in operating on the cheap. After all, these attackers seek the same high return on investment as business owners.

If you don’t believe that social engineering is a major issue, read an overview about the social engineering contest that was held this past August at Defcon 18 in Las Vegas.

One of the most alarming findings was that it doesn’t take a seasoned expert in social engineering to successfully penetrate a company. Inexperienced attackers have easy access to free resources including Facebook, LinkedIn, Twitter, Google Search, and Google Street. These resources, coupled with call centers and customer service departments that are focused on customer satisfaction, were enough to gather valuable information from most targeted companies. For the more resistant targets, there were plenty of believable pretexts to choose from (e.g., employee satisfaction survey, helpless customer, recruitment agency interviewing a former employee who just posted a resume on a job-seeking website, etc.). As a last resort, any resistance encountered was easily overcome by simply hanging up and calling again until a more cooperative employee could be reached.

The Full PDF version of the report is available for download from Social-Engineer.Org here.