Harold Hitz Burton

“ The privilege recognizes the obligation of citizens to communicate their knowledge of the commission of crimes to law-enforcement officials and, by preserving their anonymity, encourages them to perform that obligation.
The scope of the privilege is limited by its underlying purpose. Thus, where the disclosure of the contents of a communication will not tend to reveal the identity of an informer, the contents are not privileged. [7] Likewise, once the identity of the informer has been disclosed to those who would have cause to resent the communication, the privilege is no longer applicable. ”

“ Whoever fraudulently or knowingly imports or brings any narcotic drug into the United States or any territory under its control or jurisdiction, contrary to law, or receives, conceals, buys, sells, or in any manner facilitates the transportation, concealment, or sale of any such narcotic drug after being imported or brought in, knowing the same to have been imported contrary to law, or conspires to commit any of such acts in violation of the laws of the United States, shall be fined not more than $2,000 and imprisoned not less than two or more than five years. ”

“ What is usually referred to as the informer's privilege is in reality the Government's privilege to withhold from disclosure the identity of persons who furnish information of violations of law to officers charged with enforcement of that law. ”