That said, I think you have to be a stone idiot to give an online casino your credit card number and gamble over the Internet. If anyone wants to gamble that badly, just mail your money to me, and I'll offer you the same odds of getting any of it back.
Some of these online casinos are publicly-traded companies in the UK; they are subject to pretty heavy government regulation over there. The US government could have had a chunk of that revenue in the form of taxes. But Congress sold out to horse betting interests and other land-based casinos, and so, here we are.