UIGEA in practice didn’t make online gambling illegal, but made harder or impossible for US banks to accept financial transactions to online gambling websites. Law-makers just pushed the responsibility over to banks, and banks answered with a total ban of gambling related money flow.
And how US allowed casinos can work in this environment?
http://www.casinoaffiliateprograms.com/bb/how-casino-s-process-online-check-payments.28620.html?
And click on BB28’s link in the first post.