During
World War II the United Kingdom enforced a blackout of all lights that might be used by enemy aircraft to target urban areas during
the Blitz.
This included shutters or simliar on all windows and shielding street lights so they did not shine up (and did not shine anywhere else very strongly). Also the headlights of cars were masked so that they threw only a very small beam. Not unsurprisingly the number of accidents at night went up quite noticeably during this Blackout.
Enforcing the Blackout was part of the responsibility of the Air Raid Patrol (ARP) wardens. They could be obsessive and were sometimes the target of fun (as in the comedy "Dad's Army").