Confidentiality is mandated in the United States by the Health Insurance Portability and Accountability Act of 1996 known as HIPAA, specifically the Privacy Rule, and various state laws, some more rigorous than HIPAA. However, numerous exceptions to the rules have been carved out over the years. For example, many states require physicians to report gunshot wounds to the police and impaired drivers to the Department of Motor Vehicles. Confidentiality is also challenged in cases involving the diagnosis of a sexually transmitted disease in a patient who refuses to reveal the diagnosis to a spouse, and in the termination of a pregnancy in an underage patient, without the knowledge of the patient's parents. Many states in the U.S. have laws governing parental notification in underage abortion. Those working in mental health have a duty to warn those who they deem to be at risk from their patients in some countries.