You may have heard some bad things about BetOnline in the past, and suffice it to say that we heard the same things too. Of course, you still need to safeguard yourself against dishonest and shady operators who could put your funds at risk. The Wire Act, UIGEA, and other applicable statutes target only those running the sites, not individual players, so you're totally in the clear on that front.
federal government might not want you to know this, it's perfectly legal for you as an individual player to access the card games at BetOnline or any other USA-friendly online gaming site.