In any case in which the attorney general of a State has reason to believe that an interest of the residents of that State has been or is threatened or adversely affected by the engagement of any person in a practice that violates any regulation of the Commission prescribed under section
6502
(b) of this title, the State, as parens patriae, may bring a civil action on behalf of the residents of the State in a district court of the United States of appropriate jurisdiction to—