He got banned because of the huge amount of money he's gambling/winning.
He can fuck the casinos for a week if he makes off with a huge amount. I'm from Reno Nevada, which is a little ghetto Vegas. I heard from a guy who's in the top levels of management in one casino here that they need to make 200k a day just to break even on overhead. This casino is nothing like the Palms.
It has nothing to do with him being an asshole. I actually heard he's a nice guy and tips VERY WELL, to the point the cocktail waitresses and the dealers get upset when their casinos ban him because they make ridiculous amounts of tips off him.
It has everything to do with the ridiculous amount of money he bets. The casino knows they win over time, but with the variance of gambling they prefer to take bets they can handle losing if they lose. It fucks up everything if they lose a huge amount. It's a bankroll variance thing, most knowledgeable bettors/texas holdem players know what I'm talking about. It's how most people take care of their bankroll when they bet/gamble. They know it's gambling at the end of the day and people get lucky so they must be prepared to be on the unlucky side even if the odds are on their side so they don't bust their bankroll over one hand.
Edit: I really doubt he counts cards, word would get around and he wouldn't be allowed in any casino. Plus I doubt Dana is that quick. Just casinos protecting their bankrolls.