Actually there are few people who did that by some cheating methods but they were never allowed to eter into casinos because they can bankrupt their bankroll if they are continue to play there,I don't know which is true or not but I read that while I am scrolling newsfeeds.But in reality there is no way to win in long term other than cheating.
You are misinformed or did not go through the fine print. Anybody who is found cheating a casino would be restricted and the website patched to prevent such exploits again. For those who reveal bugs and such exploits that could be done are also rewarded for the same. Bottom line is if you cheat that you are plain thief and you will be tracked down by the casino owners for punishment as far as possible.
Thats where the problem comes in with anonymous currencies - they are said to be anonymous until people start using that info to track scammers. It not something bad in my opinion.