Many employers in the United States have been initiating or expanding policies requiring background checks of prospective employees. The ability to perform such checks has been abetted by the growth of computerized databases and of commercial enterprises that facilitate access to personal information. Employers now have ready access to public information that had heretofore been difficult to collect without an expenditure of considerable effort and money--criminal records, litigation history, worker-compensation claims, marriage records, bankruptcy liens, court judgments, and more. They also have ready access to private information--credit-card history, airline use, certain telephone records, bank-account histories, pharmacy records, and even records of medical visits. The ready availability of these data creates the serious possibility of promiscuous, unfair, and perhaps even abusive investigations, and yet access to these data is subject to few legal limits.1 Systematic inquiry into such personal information is nevertheless commonly understood to constitute a serious and harmful intrusion upon an individual's privacy.