My son and his cousin both 5 were playing in my parent's garden. My parents have a big garden about 200 foot but not enormous and it is surrounded by a hedge/fence all around. Anyway, they were playing outside alone which I think is completely fine.
Anyway, my son came in and said 'Is someone going to steal me?' and I said 'of course not! who said that to you?' My SIL said 'I did, because they were playing in the garden on their own, which I'm not happy about'.
I said I was fine with my DS playing outside on his own and I had to keep reassuring my DS that noone would steal him.
I think was really wrong of her to say, I have in the past had a chat with him about going off with strangers etc but have not felt it appropriate to worry him about abduction. I also feel that at 5 he is fine along/playing with his cousin in an enclosed garden!