It's not that simple. There are plenty of places where the sets "things that are legal" and "things that are moral" don't intersect. Those are some of the most interesting, challenging questions we will face.
EDIT: And I would submit the offered example illustrates that. Doing two miles per hour over the posted speed limit may not be legal, but it's hardly immoral. Similarly, lying to someone to sway their opinions in an argument isn't illegal, but I don't think that's particularly moral, is it?
Don't be so reductive.
