Stopping Harmful Incidents to Enforce Lawful Drone Use Act or the SHIELD U Act This bill authorizes Counter-Unmanned Aircraft System (C-UAS) activities on and off commercial service airport property to detect, identify, and mitigate threats posed by an unmanned aircraft (i.e., drone) or unmanned aircraft system. It authorizes the Department of Homeland Security (DHS), state and local law enforcement, and airport law enforcement to carry out these activities. Additionally, the bill allows DHS and the Departments of Defense, Justice, and Energy to contract with other entities to carry out C-UAS activities. The bill also (1) expands the Federal Law Enforcement Training Center curriculum to include use of C-UAS authorities as well as the ability for state, local, tribal, and territorial law enforcement to attend such training; and (2) allows state, local, and airport law enforcement to use jamming technology to mitigate a drone threat.