New algorithm guesses SSNs using date and place of birth - Ars Technica
http://arstechnica.com/tech-policy/news/2009/07/social-insecurity-numbers-open-to-hacking.ars

Given these numbers, the authors estimate that even a moderate-sized botnet of 10,000 machines could successfully obtain identity verifications for younger residents of West Virginia at a rate of 47 a minute.

Two researchers have found that a pair of antifraud methods intended to increase the chances of detecting bogus social security numbers has actually allowed the statistical reconstruction of the number using information that many people place on social networking sites.