The Environmental Protection Agency (EPA) v. Mink case in 1972 revolved around the issue of whether or not classified material could be withheld from Congress under the Freedom of Information Act (FOIA). The dispute began when a group of scientists, led by Congressman Patsy Mink, requested documents related to underground nuclear testing on Amchitka Island in Alaska. The EPA refused to release some documents citing national security concerns and executive privilege. This led to a lawsuit where the Supreme Court ruled that courts could not review classified documents for possible declassification and public release under FOIA requests. However, it also held that non-classified portions must be disclosed unless they are "inextricably intertwined" with classified parts such that their disclosure would reveal sensitive information.

In the dissenting opinion for the case of Environmental Protection Agency et al. v. Mink et al., Justice William O. Douglas argued that Congress intended to make government information available to citizens unless it fell under specific exemptions, and this should include classified documents related to environmental issues. He believed that courts should have the power to review classified material in camera (in private) if a dispute arises over its status, rather than relying solely on an agency's assertion that it is exempt from disclosure due to national security reasons as stated in exemption 1 of FOIA (Freedom Of Information Act). In his view, allowing agencies such unchecked authority undermines public trust and accountability while potentially hiding crucial information about environmental hazards or other matters of public concern.