Buttons: Section 3121. General Prohibition On Pen Register And Trap And Trace Device Use; Exception, Section 3123. Issuance Of An Order For A Pen Register Or A Trap And Trace Device, and Section 1073: The Foreign Intelligence Surveillance Act (FISA) -- 50 U.S.C. § 1809. Lanes of the Road quadrant displays LE (Law Enforcement) and WF (Warfighter).