Empowering Children
I think children really need to be given the tools many times throughout their childhood to deal with situations like this. Telling a child "don't talk to strangers" or "don't get into a stranger's car" is absolutely not enough.
I think the number one thing that keeps a child from getting help, even if it's a short window of opportunity, is fear. The attacker/kidnapper threatens them or their family with harm. Kids have to be taught that in those situations, it is better to tell someone, anyone, make a scene, and not fear about being harmed. Even children who are not kidnapped but being abused, they need to be taught that no harm will come to them from speaking up, even if that's what they were told. We need to start empowering kids, teaching them to have a voice, teaching them to physically fight back if harmed, like kicking, biting, scratching, etc. A child with a voice is a powerful weapon against predators.
When I was a child, I had a good friend who was being abused by another friend's dad. No one knew. One day, at 10 years old, she got the courage to speak up, despite the threats, and tell someone. The father may have been the abuser, but, she had the power to stop it, and she did. For that, she will always be my hero, I can't imagine how courageous she had to have been. We have to teach kids about the lies they will be told and to find courage to rise above those lies and find help.
Of course horrible situations like these will happen, but, let's empower kids to give them a fighting chance.