The problem I see is that online poker is explicitly illegal in a number of states in the US (e.g. - Washington, Illinois, Iowa). Similar to handicapping horse racing under the Wire Act, in these states it does not matter whether poker is a skill-based activity. If the sites allowed players from those states to play, I can't see how they avoid (at a minimum) the money laundering charges short of showing those state anti-online poker laws are invalid. Further (and more broadly), I think the Feds can easily back door the money laundering/structuring charges via those winning online players that did not declare income from poker.