“Curious, I took 100M samples and found that only 31% of the rows had unique SSNs, so extrapolating that out, 2.9B would be more like 899M.”
National Public Data sold background checks built on the names, addresses and SSNs of people who never agreed to be in its files. A seller listed 2.9 billion rows for $3.5 million in April, and the SSN data went public in August. The headline number is inflated, but 899 million unique SSNs in plain text is still a disaster. The only people missing were the ones who had used data opt-out services.