(This probably isn't very original and maybe is too easy, but I came up with it on my own and figured I'd post it anyway.)
Masked strangers forcibly took a baby from her mother at knifepoint. In the process, the mother was cut and needed a blood transfusion. The baby was terrified and screaming throughout the ordeal, but she eventually was returned to her mother and father, who didn't file charges. (Instead, the parents were charged!) Why?