I'm fairly certain your assumption is correct. That probably counts as a form of digital IP protection (blocking content not licensed to a particular country), and under the US's DMCA, circumventing such things is illegal. Or at least, I can see that argument being made. It is, after all, a way of gaining access to something outside the proper, legally-established channel. However, I haven't come across anything yet to settle it one way or another, but I might just be sucking at the internet atm.