Substantial Government Interests
First, there must be a "substantial" government interest that informs the regulatory scheme pursuant to which the inspection is made.
("substantial federal interest in improving the health and safety conditions in the Nation's underground and surface mines");
(regulation of firearms is "of central importance to federal efforts to prevent violent crime and to assist the States in regulating the firearms traffic within their borders");
(federal interest "in protecting the revenue against various types of fraud").