According to my opinion, for such high payouts, Stunna should implement some verification measures in order to be able to check the bets and also about the identity of the player itself...
I think part of the appeal of PrimeDice for many is that they don't require players to identify themselves. Changing that to "... unless you win too much" makes it less attractive I expect.
I said it in the context that such bets should be verified before allowing any withdrawals, even if players here are to maintain their anonymity, no worries at all, and I don't think players should have any problems getting their bets verified...