I actually made my children watch this too.
I've seen something similar before where a man had lost his dog and asked the children to help find it with him. The children think they are doing a good thing by helping someone!!
This is a worst nightmare for most parents. What do you think your child would do? Will watching this clip make you talk through stranger danger again with your child and maybe show them the clip?
I also dread my children getting lost in a crowded place, the elder ones know my mobile number but my little boy is still a bit young so I just tell him to find another mummy and ask for help. What have you told you children to do?