If you have evidence that it's not the case, especially for the majority, in other words, you have enough evidence to accuse thousands of people of crime, why are you not in touch with the police yet?
Obviously I don't have evidence, but it's just common sense. They have huge incentives to cheat, very few incentives to play it safe.
And it's very hard to get evidence and prove guilt.
Do you really think people gambling with billions of dollars are doing so without an edge?