New Orleans—Starting with a birth date, sex, and ZIP code, computer privacy expert Latanya Sweeney, PhD, retrieved health data of William Weld, former governor of Massachusetts, from an allegedly anonymous database of state employee health insurance claims. Knowing Weld lived in Cambridge, Mass, she cross-linked her data with that community's publicly available voter registration records. Only six people shared Weld's birth date. Only three were men. Of these, Weld was the only man in his five-digit ZIP code.
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