Wikipedia
Parens patriae is Latin for "parent of the nation" (lit., "parent of the fatherland"). In law, it refers to the public policy power of the state to intervene against an abusive or negligent parent, legal guardian or informal caretaker, and to act as the parent of any child or individual who is in need of protection. For example, some children, incapacitated individuals, and disabled individuals lack parents who are able and willing to render adequate care, thus requiring state intervention.
In U.S. litigation, parens patriae can be invoked by the state to create its standing to sue; the state declares itself to be suing on behalf of its people. For example, the Hart-Scott-Rodino Antitrust Improvement Act of 1976 (), through Section 4C of the Clayton Act, permits state attorneys general to bring parens patriae suits on behalf of those injured by violations of the Sherman Antitrust Act.