Basically, the term "free range children refers to children who are allowed to roam around the neighborhood or even town without immediate supervision. The desirability of this concept seems to be founded in books like Mark Twain's Tom Sawyer and Huckleberry Finn. To be sure, nineteenth-century river towns probably had fewer perils than large cities do today. Also, there was less widespread awareness of those possible threats. Some parents told their children to beware of the boogerman (or bogeyman). Was this term a euphemism for a child molester or killer?
Some proponents of free-range parenting occasionally elicit visits from Child Protective Services because others see her or his style to be neglectful of their children. One set of parents got called out because they allowed their eight year old daughter go on the subway unaccompanied. In response, the free-range children parenting advocates have organized free-range play groups, free-range playgrounds, and free-range Sunday School classes.
Organized free-range groups: is that an oxymoron?
Anyway, I was told when I was young that I could ride my bike anywhere in Lakeview (in big, bad New Orleans) up to the railroad underpass and Larry's Homedale Inn. Alas, Tad Gormley Stadium was not in that area, but the Mardi Gras Fountain, Harrison Avenue, and Rockery Inn were. We once put detergent in the fountain! I made it into adulthood.
Needless to say, the French Quarter and the Central Business District were far away.
The point is, peoples' ideas about proper parenting change, sometimes this is related to the real-life situations that children have to be in. Parents should understand the child's neighborhood. And so should nosy bystanders.