One Among The Ruins

I had a thought: RFID bracelets for kids at amusement parks. I wouldn't think it would be too difficult to set up sensors and various portions of a park and all exits. Maybe there would be some sort of phone app compatibility. You tell it the ID number of your kids bracelet and it tells you all locations tripped by the bracelet in order by time stamp.

Perhaps overlaid by a map of the amusement park? Or maybe the sensor locations would trigger an alarm if the child's bracelet passes through without a similar bracelet worn by the parent passing through as well?

Would this prevent kids from getting lost or abducted? I wonder if Disney takes suggestions.