18 U.S.C. § 2251 : US Code - Section 2251: Sexual exploitation of children

      (a) Any person who employs, uses, persuades, induces, entices, or
    coerces any minor to engage in, or who has a minor assist any other
    person to engage in, or who transports any minor in or affecting
    interstate or foreign commerce, or in any Territory or Possession
    of the United States, with the intent that such minor engage in,
    any sexually explicit conduct for the purpose of producing any
    visual depiction of such conduct or for the purpose of transmitting
    a live visual depiction of such conduct, shall be punished as
    provided under subsection (e), if such person knows or has reason
    to know that such visual depiction will be transported or
    transmitted using any means or facility of interstate or foreign
    commerce or in or affecting interstate or foreign commerce or
    mailed, if that visual depiction was produced or transmitted using
    materials that have been mailed, shipped, or transported in or
    affecting interstate or foreign commerce by any means, including by
    computer, or if such visual depiction has actually been transported
    or transmitted using any means or facility of interstate or foreign
    commerce or in or affecting interstate or foreign commerce or
    mailed.
      (b) Any parent, legal guardian, or person having custody or
    control of a minor who knowingly permits such minor to engage in,
    or to assist any other person to engage in, sexually explicit
    conduct for the purpose of producing any visual depiction of such
    conduct or for the purpose of transmitting a live visual depiction
    of such conduct shall be punished as provided under subsection (e)
    of this section, if such parent, legal guardian, or person knows or
    has reason to know that such visual depiction will be transported
    or transmitted using any means or facility of interstate or foreign
    commerce or in or affecting interstate or foreign commerce or
    mailed, if that visual depiction was produced or transmitted using
    materials that have been mailed, shipped, or transported in or
    affecting interstate or foreign commerce by any means, including by
    computer, or if such visual depiction has actually been transported
    or transmitted using any means or facility of interstate or foreign
    commerce or in or affecting interstate or foreign commerce or
    mailed.
      (c)(1) Any person who, in a circumstance described in paragraph
    (2), employs, uses, persuades, induces, entices, or coerces any
    minor to engage in, or who has a minor assist any other person to
    engage in, any sexually explicit conduct outside of the United
    States, its territories or possessions, for the purpose of
    producing any visual depiction of such conduct, shall be punished
    as provided under subsection (e).
      (2) The circumstance referred to in paragraph (1) is that - 
        (A) the person intends such visual depiction to be transported
      to the United States, its territories or possessions, by any
      means, including by using any means or facility of interstate or
      foreign commerce or mail; or
        (B) the person transports such visual depiction to the United
      States, its territories or possessions, by any means, including
      by using any means or facility of interstate or foreign commerce
      or mail.

      (d)(1) Any person who, in a circumstance described in paragraph
    (2), knowingly makes, prints, or publishes, or causes to be made,
    printed, or published, any notice or advertisement seeking or
    offering - 
        (A) to receive, exchange, buy, produce, display, distribute, or
      reproduce, any visual depiction, if the production of such visual
      depiction involves the use of a minor engaging in sexually
      explicit conduct and such visual depiction is of such conduct; or
        (B) participation in any act of sexually explicit conduct by or
      with any minor for the purpose of producing a visual depiction of
      such conduct;

    shall be punished as provided under subsection (e).
      (2) The circumstance referred to in paragraph (1) is that - 
        (A) such person knows or has reason to know that such notice or
      advertisement will be transported using any means or facility of
      interstate or foreign commerce or in or affecting interstate or
      foreign commerce by any means including by computer or mailed; or
        (B) such notice or advertisement is transported using any means
      or facility of interstate or foreign commerce or in or affecting
      interstate or foreign commerce by any means including by computer
      or mailed.

      (e) Any individual who violates, or attempts or conspires to
    violate, this section shall be fined under this title and
    imprisoned not less than 15 years nor more than 30 years, but if
    such person has one prior conviction under this chapter, section
    1591, chapter 71, chapter 109A, or chapter 117, or under section
    920 of title 10 (article 120 of the Uniform Code of Military
    Justice), or under the laws of any State relating to aggravated
    sexual abuse, sexual abuse, abusive sexual contact involving a
    minor or ward, or sex trafficking of children, or the production,
    possession, receipt, mailing, sale, distribution, shipment, or
    transportation of child pornography, such person shall be fined
    under this title and imprisoned for not less than 25 years nor more
    than 50 years, but if such person has 2 or more prior convictions
    under this chapter, chapter 71, chapter 109A, or chapter 117, or
    under section 920 of title 10 (article 120 of the Uniform Code of
    Military Justice), or under the laws of any State relating to the
    sexual exploitation of children, such person shall be fined under
    this title and imprisoned not less than 35 years nor more than
    life. Any organization that violates, or attempts or conspires to
    violate, this section shall be fined under this title. Whoever, in
    the course of an offense under this section, engages in conduct
    that results in the death of a person, shall be punished by death
    or imprisoned for not less than 30 years or for life.