Now when you say young winning, are you withdrawing your funds? Try to make a withdrawal and let us know from there. If you input 0.001BTC an win 1BTC but can never withdraw it then you didn't really 'win' anything now did you?
999Dice isn't scamming by blocking withdrawals. The only question is the provably fair system. I have cashed out 4+ BTC at once from 999 once. More than 1 BTC many times.
Edit: Though there's no certainty they would pay out big money. Just haven't heard of them refusing to pay.
This issue runs fast, although people didnt played here but others keep saying that 999dice is scam so many of them wont even try to put some balance to play there. With some scam accusation, the will to not playing here is higher enough more over with some little proof. May be for some rich guy they want to try it though but others that have only little money wont really take some part into this kind of site even though they havent try it yet