When retailers do sell to people under 21, cities have their own fine and discipline scale
It works really well
See also the local law Carlsbad Ordinance 8.16.015 ((a) No person shall, without first obtaining permission from the chief of police as required by Section 8.16.020, shoot or discharge any air rifle, air gun, BB gun, pellet gun, gas-operated gun, spring gun or any other weapon designed to discharge or propel any projectile capable of causing injury on any public property, or on any street or sidewalk, whether public or private, or in any park, beach, golf course, shopping center, or other public gathering place within the city.)
Use this when telling someone something is off limits
In Sudan, its widely practiced among young population