Law professor and free-range dad David Pimentel carefully reviews the legality of free-range parenting.  Just one case:

In State v. Hughes, a father was convicted in a bench trial for leaving his 5-year-old daughter in the air-conditioned cab of his pickup truck, watching a cartoon on a DVD player, equipped with a cell phone she knew how to use, while he ran into the store. The court of appeals reversed, over a vehement dissent, noting that the Ohio statute required that the father’s neglect create a “substantial risk” or a “significant possibility” of harm to the child. The prevailing opinion (not joined by the concurring judge) detailed the various sequences of events that would be necessary for this child to be harmed during the 27 minutes she was alone, and found them to be speculative. The majority was careful not to endorse the father’s conduct, however, only concluding that the facts did not justify criminal conviction…

In absolute terms, I’m not worried about being persecuted by child welfare services.  But power-mad bureaucrats probably outnumber kidnappers and serial killers at least a thousand to one.