casino winnings are not taxed unlike in the US. If you win a million Ringgit here, you get to keep that cool million, not having to pay any tax for it.
Whereas in the US, when you win in lotteries or in casinos or even come into any financial gains, the winnings or gains is subjected to a 30% withholding tax. All is not lost, however.
Canadian and International visitors to the US can make a claim of the 30% withholding tax which is a good thing to offset one's gaming losses. You could recoup at least some or all of the gambling winnings tax.
One company that provides U.S. Gambling Tax Recovery services is http://www.casinotaxrebate.com/. As an IRS authorized Certifying Acceptance Agent (ID # 98-0337122) they can get you an Individual Taxpayer Identification Number and provide you with all the necessary service to help you with the US tax recovery. If you don't get your casino refund cheque they don't charge a fee.