Sure, they can write you a check. Your bank might reject it if it says COSTA RICA SPORTSBOOK on it, but if it says J&J Enterprises how the hell are they going to know who sent it. Same thing with bank wires.
People are you that dense to not realize NOTHING is that obvious in this business? Everything is done with agents and pseudonym name accounts. A bank isn't going to have a CLUE where the money came from and if they don't they aren't just going to ban everything you deposit. This is part of the banking argument, they won't support this gaming bill unless it holds them without liability for enforcement. The whole basis of this bill is flawed from enforcement standpoint because in the end its all going to be about the books saying we won't take the deposit or pay it out. And of course the books are going to thumb their noses at the US Congress if they pass this.