You think they are in buisness because their websites are "fair" your joking right? Here is a defenition of provably fair " algorithm which can be analyzed and verified for fairness on the part of the service operator." thats right, the number is not generated until you place a bid, only then is the seed "randomly" generated, you dont see a problem with that? Its no different then calling head or tails on a coin flip, right after it was flipped already, and you can visually see the coin.