Offshore and online gambling is illegal. There was something called the "Wire Act" in 1961, which banned all gambling over a telephone, and Congress has stated that internet gambling is similar to gambling over a telephone. In 2006... they passed the "Unlawful Internet Gambling Act", which banned all gambling on the Internet. Luckily, they're not arresting the people who are actually gambling, but instead, they are going after the companies that are sponsoring the gambling. At the moment, it is illegal for Americans to gamble on the internet.