Problem:
Dow chemical company operated a 2,000-acre chemical manufacturing facility at Midland, Michigan. The facility consisted of numerous covered buildings, with manufacturing equipment and piping conduits between various buildings plainly visible from the air. Dow maintained elaborate security around the perimeter of the complex to bar ground-level public views of these areas. It also investigated any low level flights by aircraft over the facility. Dow did not, however, attempt to conceal all manufacturing equipment within the complex from aerial views because the cost would have been prohibitive. With Dow's consent, enforcement officials of the Environmental Protection Agency (EPA) made an on-site inspection of two power plants in the complex. When Dow denied EPA's request for another inspection, EPA did not seek an administrative search warrant. Instead, EPA employed a commercial aerial photographer, who used a standard floor-mounted precision aerial mapping camera to take photographs of the facility from altitudes of 12,000, 3,000 and 1,200 feet. At all times, the aircraft was lawfully within navigable airspace. EPA did not inform Dow of this aerial photography.
Was EPA's taking of aerial photographs of the Dow complex a search prohibited by the Fourth Amendment?