Section 1028(e) of Title 18 provides that 18 U.S.C. § 1028:
does not prohibit any lawfully authorized investigative, protective, or intelligence activity of a law enforcement agency of the United States, a State, or a political subdivision of a State, or of an intelligenceagency of the United States, or any activity authorized under chapter 224 of this title.
Chapter 224 is the basis of the Federal Witness Security Program administered by the United States Marshals Service in which persons who have cooperated with federal prosecutors and investigators, and who may be the subject of retaliation by the defendant or his confederates, are enabled to relocate and establish new identities for themselves and their families. The authorized production and transfer of identification documents by United States employees to protected persons and undercover personnel would be excluded from section 1028 as would the lawful use of these documents by the protected person, his family, and the undercover personnel. This subsection is intended to provide immunity analogous to that afforded in 21 U.S.C. § 885(d). The term "lawfully authorized" describes functions approved in accordance with an agency's rules and practices. It does not excuse conduct by a law enforcement officer who has gone on a lark of his own.
[cited in JM 9-64.400]