Kids are very tech savvy these days, and that can cause some serious trouble when it comes to microtransactions and in app payments.
Sometimes you might have left your account logged in with your payment details (we strong suggest you don't do this) and other times your little ones might cleverly figure out a way to but something in an app without your knowledge.
A new ruling in California has made it possible to get a refund for payments made through Facebook if they were made by a minor. This follows on from a case in 2012 where several hundred dollars worth of Facebook credits were purchased by two young children.
It all has to do with the kids being minors, who are not in a position to make financial decisions themselves. They technically entered into a contract with Facebook, which they're not legally able to do until the age of 18.
So if something like this does happen to you, contact the relevant service as soon as possible and explain the situation.