Here is a story from CHCH about a 10-year old girl in Ajax that was approached by a man and woman telling her that her mom sent them to pick her up.
Parents are always encouraged to use code words with their kids. This way if a stranger approaches them and uses that story, they’ll know not to go with them.
http://www.chch.com/home/item/12128-quick-action-thwarts-abduction-attempt