Which amendment is most closely associated with privacy issues?

The Ninth Amendment is most closely associated with privacy issues because it explicitly addresses the idea that the listing of specific rights in the Constitution does not mean that other rights do not exist. This amendment has been interpreted to protect unenumerated rights, which include various aspects of personal privacy that are not explicitly outlined in the Constitution. For example, the Supreme Court in cases such as Griswold v. Connecticut has invoked the Ninth Amendment to recognize a right to privacy concerning marital relations and contraception.

While the Fourth Amendment is also significant in discussions of privacy, particularly in protecting against unreasonable searches and seizures, it is more specifically focused on the security of persons, houses, papers, and effects. The Fifth Amendment includes rights related to self-incrimination and due process but does not directly address privacy in a broader sense. The Tenth Amendment reserves powers not delegated to the federal government to the states or the people, but it is not directly tied to privacy.

The Ninth Amendment's emphasis on the protection of rights that are not expressly stated aligns closely with the broader philosophical and legal considerations surrounding personal privacy.