SrCheetah, yes kids are vulnerable to that, but you're forgetting something. Its their parents' credit card. The one's responsible for it is the parents, so if the don't ask they child "what is it you're trying to get", then its their fault.

When I was growing up and I wanted to use my moms' credit card I had to explain to her, what it was I was getting, why I needed it, etc... Its not like she was being stingy either, she was just making sure I knew what I was doing and that I actually wanted it. Then after that I would pay her in cash from my money for the purchase I made. So don't play the "they don't know any better" card here, the only ones that don't know better are the parents if the kid gets scammed.