18 U.S.C. § 2252. Certain activities relating to material involving the sexual exploitation of minors
(a) Any person who--
(1) knowingly transports or ships in interstate or foreign commerce by any means including by computer or mails, any visual depiction, if--
(A) the producing of such visual depiction involves the use of a minor engaging in sexually explicit conduct; and
(B) such visual depiction is of such conduct;
(2) knowingly receives, or distributes, any visual depiction that has been mailed, or has been shipped or transported in interstate or foreign commerce, or which contains materials which have been mailed or so shipped or transported, by any means including by computer, or knowingly reproduces any visual depiction for distribution in interstate or foreign commerce or through the mails, if--
(A) the producing of such visual depiction involves the use of a minor engaging in sexually explicit conduct; and
(B) such visual depiction is of such conduct;
(3) either--
(A) in the special maritime and territorial jurisdiction of the United States, or on any land or building owned by, leased to, or otherwise used by or under the control of the Government of the United States, or in the Indian country as defined in section 1151 of this title, knowingly sells or possesses with intent to sell any visual depiction; or
(B) knowingly sells or possesses with intent to sell any visual depiction that has been mailed, or has been shipped or transported in interstate or foreign commerce, or which was produced using materials which have been mailed or so shipped or transported, by any means, including by computer, if--
(i) the producing of such visual depiction involves the use of a minor engaging in sexually explicit conduct; and
(ii) such visual depiction is of such conduct; or
(4) either--
(A) in the special maritime and territorial jurisdiction of the United States, or on any land or building owned by, leased to, or otherwise used by or under the control of the Government of the United States, or in the Indian country as defined in section 1151 of this title, knowingly possesses 1 or more books, magazines, periodicals, films, video tapes, or other matter which contain any visual depiction; or
(B) knowingly possesses 1 or more books, magazines, periodicals, films, video tapes, or other matter which contain any visual depiction that has been mailed, or has been shipped or transported in interstate or foreign commerce, or which was produced using materials which have been mailed or so shipped or transported, by any means including by computer, if--
(i) the producing of such visual depiction involves the use of a minor engaging in sexually explicit conduct; and
(ii) such visual depiction is of such conduct;
shall be punished as provided in subsection (b) of this section.
(b)(1) Whoever violates, or attempts or conspires to violate, paragraphs [sic] (1), (2), or (3) of subsection (a) shall be fined under this title and imprisoned not less than 5 years and not more than 20 years, but if such person has a prior conviction under this chapter, chapter 71, chapter 109A, 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, or abusive sexual conduct involving a minor or ward, 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 15 years nor more than 40 years.
(2) Whoever violates, or attempts or conspires to violate, paragraph (4) of subsection (a) shall be fined under this title or imprisoned not more than 10 years, or both, but if such person has a prior conviction 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 aggravated sexual abuse, sexual abuse, or abusive sexual conduct involving a minor or ward, 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 10 years nor more than 20 years.
(c) Affirmative defense.--It shall be an affirmative defense to a charge of violating paragraph (4) of subsection (a) that the defendant--
(1) possessed less than three matters containing any visual depiction proscribed by that paragraph; and
(2) promptly and in good faith, and without retaining or allowing any person, other than a law enforcement agency, to access any visual depiction or copy thereof--
(A) took reasonable steps to destroy each such visual depiction; or
(B) reported the matter to a law enforcement agency and afforded that agency access to each such visual depiction.