While the federal government has a clear interest in protecting gambling websites and the people who participate in them, enforcement of federal gambling laws is subject to legal challenges. Among these challenges are those based on the Commerce Clause, the First Amendment guarantee of free speech, and the Due Process Clause. While Commerce Clause doubts are mostly satisfied by the commercial nature of the gambling industry, free speech objections have more difficulty since First Amendment protections for speech related to crime are often limited. Due process arguments are also limited when financial transactions are involved.
While gambling is largely a matter of state law, federal law can be used to supplement state gambling laws. Some state officials have expressed concern that the internet can be used to bring illegal gambling into their jurisdictions. These states are attempting to combat this risk through a wide variety of measures. For example, the Unlawful Internet Gambling Enforcement Act has been a source of concern for states.
Depending on the type of gambling, the laws surrounding online gambling differ. According to 31 U.S.C. 5362(10), internet gambling is illegal if it involves placing, receiving, or transmitting bets on the internet. This includes sports betting. It is also against the law to conduct wagers on interstate commerce.