In case anyone had any doubts of how Scalia views prosecutorial zealousness, we get this historical charm from his concurral in Whitman v. United States.
I doubt the Government’s pretensions to deference. They collide with the norm that legislatures, not executive officers, define crimes. When King James I tried to create new crimes by royal command, the judges responded that “the King cannot create any offence by his prohibition or proclamation, which was not an offence before.” Case of Proclamations, 12 Co. Rep. 74, 75, 77 Eng. Rep. 1352, 1353 (K. B. 1611). James I, however, did not have the benefit of Chevron deference. See Chevron U. S. A. Inc. v. Natural Resources Defense Council, Inc., 467 U. S. 837 (1984). With deference to agency interpretations of statu- tory provisions to which criminal prohibitions are at- tached, federal administrators can in effect create (and uncreate) new crimes at will, so long as they do not roam beyond ambiguities that the laws contain. Undoubtedly Congress may make it a crime to violate a regulation, see United States v. Grimaud, 220 U. S. 506, 519 (1911), but it is quite a different matter for Congress to give agencies— let alone for us to presume that Congress gave agencies— power to resolve ambiguities in criminal legislation, see Carter v. Welles-Bowen Realty, Inc., 736 F. 3d 722, 733 (CA6 2013) (Sutton, J., concurring).