Yes, my 4 year old Ivan play the Facebook game Angry Birds Friends. I even didn’t know there’s such game exist in Facebook! I bought 3,000 coins 2 times! Luckily, one can ask for a refund for accidental purchase or something like for my case. Ivan doesn’t know that he’s making a purchase.
I had cancel the automatic fund transfer of PayPal to Facebook.
I hope this would not happen again.