Much obliged! 
Nope, I meant one should simply warn users, not block them altogether. For example, Pandora does this awfully - they block their site almost completely to non-US visitors. My solution would entail something as simple as horizontal bar at the top of the page, or a nice, user friendly warning. In fact, they do have one (if you paste in +5555555 as the number), but it’s malfunctioning - that one would be quite enough.
The website should most definitely stay accessible to all and should be able to convey information, but the service should be gently restricted.