Out in California, a woman is suing Facebook because her teenage son bought the social network's virtual currency to spend in video games, and that transaction should be illegal under the state's consumer protection laws.
Glynnis Bohannon, reports Gamasutra, is suing to have the purchases refunded to her, and for all other purchases of this type to be refunded to other parents, up to $5 million. No other damages or amounts were mentioned. So while this $5 million is not entirely her claim, it sounds like the case would have the potential to become a class action.
Facebook allows children as young as 13 to create pages but requires them to get parental approval first before making any purchases through the site. Bohannon's complaint says that is not enough under California state law.
Gamasutra has more details and a rather robust discussion about everyone's responsibility in this. I recommend reading both as, inevitably, this is going to devolve to another seminar on parenting.