Its easy to abduct your children
If someone said to you that any stranger could walk up to your children and take them will you believe it? Children with special needs may be even more vulnerable. Merely telling children not to talk to strangers is not enough, you will have to visually show them. Watch this social experiment:
I have seen how easy it is for a child to be abducted and all the words in the world do not mean anything. The child has to understand and just telling them to say no to a stranger is not enough. Teach them. Educated them. Have them always be with a friend.
There are many ways to combat an abduction. Every situation is different so there is never going to be one right answer to save your child from a possible abduction. Awareness of the dangers is the best solution.