In the USA, there is a law called the Federal Wire Act of 1961. This law dictates that an American can not use the phone lines to place a bet. So, its against the law for Ralph Kramden in Brooklyn. NY to telephone his bookie in Las Vegas to place a USD $ 100 bet on the New York Giants Football team at the Superbowl. He has to physically GO to Las Vegas and bet there. The problem is that the law was written before the internet existed, so no one had a clue this technology would develop.
Also search the Supreme court ruling against uslotto.com an Indian gaming operation that lost !
No one can OWN and/or OPERATE a casino in the USA without a license. WIGC, a New York State corporation had a casino server in Antigua (Caribbean Nation) and ran its gambling operations from there. In July of 1999, they were found guilty in a New York State court of violating Gambling laws. The judge indicated that the casino server could be anywhere (including the planet Mars), but if the company is incorporated within a US State (ie: New York), then the company and its operations are subject to its own State's laws. On February 28, 2000, Jay Cohen, a online gaming operator based in Antigua whose casino was taking bets from Americans, was found guilty on all counts of violating the Federal Wire Act of 1960. On August 9, 2000, he was fined USD $ 5000 and was sentenced to 21 months in prison. In June of 2002, his appeal to the US Supreme court was rejected and he must serve the full sentence.
http://www.msnbc.com/news/369978.asp?cp1=1
There are several bills in Congress and the Senate making online gambling illegal
that haven't passed yet. Because of this mindfield and court rulings against Visa and MasterCard almost all US Card Issuers code their credit cards to be blocked on Gambling sites.
There are some countries that allow processors to still process blocked (Coded) credit cards as long as it is issued outside their country. There was recently a court ruling in Australia that the gaming industry won which allows them them process credit cards gor gaming as long as it's issued outsite Australia.
This transfers the criminal act on paying for gambling or betting online to the card holder in which case is anyone anywhere in the USA that uses a communications device to place the bet !