18 U.S.C. ยง 3124
United States Code, 2018 Edition
Title 18 - CRIMES AND CRIMINAL PROCEDURE
PART II - CRIMINAL PROCEDURE
CHAPTER 206 - PEN REGISTERS AND TRAP AND TRACE DEVICES
Sec. 3124 - Assistance in installation and use of a pen register or a trap and trace device
From the U.S. Government Publishing Office,