When I was young — ages 0 to 8 — my family lived in Chicago. One day I was walking down a sidewalk, and some older boys were walking the other way.
I was a little kid and pretty much just going “La la la la ...” down the sidewalk when the boys stopped me. One of them asked, “Are you M’s brother?”, where “M” refers to one of my sisters. I said something like, “Sure, yes, how you doing?”, when he hauled off and punched me in the stomach. “That’s for your sister,” he said.
(As the saying goes, Hurt people hurt people.)