Yes it happened. My 6 yr old spent $450 on apps by mistake. Well not really by mistake, he just didn’t know he was actually buying them. Considering I teach people how to protect themselves and their children while online, this was quite embarrassing.
How it happened: My wife went to buy an app for him and accidentally turned off parental controls (this is what we think happened).
What he did: He bought several apps as well as in game add ons, like fake money, that could be used for in game purchases. There were several $100 charges for in game cash.
How I found out: Google emailed me thanking me for my purchase and then paypal contacted me telling me there was unusual activity
How did I solve the problem:
1. I checked the tablet and turned parental controls back on (they were off)
2. I contacted google who refunded all of the money within minutes
What did we do to my son: We used this as a learning experience for all of them (I have 3 kids). He was 6 so didn’t quite get what he was doing. My 8 yr old would of known full well what he was doing. So we spent some time going through all of the rules (though we have done this many times)
Here is a video where I explain the whole situation in more detail: