DislikedI did try this myself.
My friend in Germany turned me on to trading, first by teaching me about CFD's. When I returned to the U.S., I wanted to get started trading them in demo. Broker after broker turned me down, saying "residents of the U.S. cannot trade CFD's". I looked into it (my German friend could not believe it), and found out it's true. I believe the U.S. is the only country where you cannot trade CFD's.
So it seems that any forex regulations that would have similar restrictions for foreign brokers applied to U.S. residents would...Ignored
No business wants to get in trouble for a few bucks, try to take a PI insurance out here in Australia for the US and Canada and then compare the return made with US clients against the premium paid, not worth it.