“Legal secrets” are secrets that the law of torts or contracts either require to be—or protect from being—divulged. The secrets themselves are without limit: a professor's past as a former priest, things learned while in a previous job, that a house has running water only twelve hours each day, that land was worth more than its owner realized, that a patient told his psychotherapist that he planned to kill his girlfriend, that the Treaty of Ghent was signed ending the War of 1812, and on and on. The legal flags under which these battles for the control of secret information are fought reduce to the law of fraud, privacy, trade secrets, and implied warranties. And the underlying economic or other principles that are proposed to explain the decisions in these areas of law are even fewer.