; and (ii) common carriers subject to the Communications Act of 1934 ( 47 U.S.C. 151 et seq.). (3) Rulemaking authority The Commission shall promulgate regulations under this Act in accordance with section 553 of title 5, United States Code. (b) Enforcement by States (1) Authorization Subject to paragraph (3), in any case in which the attorney general of a State has reason to believe that an interest of the residents of the State has been or is threatened or adversely affected by the engagement of an online service provider in a practice that violates section 3, the attorney general of the State may, as parens patriae, bring a civil action against the online service provider on behalf of the residents of the State in an appropriate district court of the United States to obtain appropriate relief, including civil penalties in the amount determined under paragraph (2). (2) Civil penalties An online service provider that is found, in an action brought under paragraph (1), to have knowingly or repeatedly violated section 3 shall, in addition to any other penalty otherwise applicable to a violation of section 3, be liable for a civil penalty equal to the amount calculated by multiplying— (A) the greater of— (i) the number of days during which the online service provider was not in compliance with that section; or (ii) the number of end users who were harmed as a result of the violation