The 2006 Unlawful Internet Gambling Enforcement Act (UIGEA) specifically exempted games of skill, which includes fantasy sports. Since then, several states have explicitly legalized fantasy sports, or prohibited them by classifying them as gambling.
Players who are residents of, or located in, the following states are prohibited from playing on Fanball (“prohibited players”): Alabama, Arizona, Delaware, Hawaii, Idaho, Iowa, Louisiana, Montana, Nevada, Vermont, and Washington State.