Not hard at all, depending on your deposit/withdraw method, you will typically have the funds in your bank account (or you receive a check) within 10 business days. Legislation is up in the air right now but that doesn't mean US players are banned from all poker sites. Play away my friend.
I keep reading that gamming online in the usa is not aloud. Well lets say you are in the USA and win some real cash on one of the sites. How hard is it going to be to collect my moneys?