AbS

Hello I am new here as I am thinking about joining the game but one thing concerns me a little which maybe someone can answer. How can players be sure that others are definitely over 18? I know that we can join with a credit or debit card, but I have seen adverts for children's bank accounts with Visa cards recently, so surely it wouldn't be possible to differentiate between those who are over or under 18 who join with a card? Or is there some other safeguard in place? Thanks for your help!