Social Security Numbering System Is Vulnerable to Fraud, Researchers Say - NYTimes.com
"The accuracy of the prediction system increased for smaller states and for people born after 1988. The accuracy was higher for those born in the late 1980s and after because of rules that led increasingly to the assignment of Social Security numbers at birth. The researchers, for example, reported that they needed 10 or fewer tries to predict all nine digits for 1 out of 20 Social Security numbers assigned in Delaware in 1996."