Even if they do it for fun, that doesn't mean they can use their money to gamble. They have to pay attention that there is a big risk of losing at gambling and if they can't control themselves, they can lose a lot of money, which has been proven by the many people who lose at gambling. If you still want to play gambling, you need good control not to lose much money. Playing gambling is a choice; no one forces you to play and let other people play.