The Unlawful Internet Gambling Enforcement Act (UIGEA) was a controversial piece of legislation that prohibited online gambling in 2006.
The act led to a number of publicly traded online poker companies, such as PartyPoker, leaving the US market in 2006.
Fortunately, some of the individual states have started to legalize online poker and the major online companies have been returning to the USA. The Poker Players Alliance has also helped to change the way online poker is perceived. The future of online poker seems to be quite bright in the United States.