I keep hearing stories of parents whose children gave away their credit card details to some strangers on the Internet. Every time something like this happens, I try to imagine how it would be like if my children gave my credit details to somebody that I do not know. It seems that there are many malicious Internet users out there who would do anything to encourage your child or children to give away your personal details.
One advice is to teach your children to never give any personal information to anybody on the Internet. If your children want to use your credit card details to pay for an online game for example, supervise the transaction yourself.