I'd be too scared to travel to ANY Police State (China, North Korea, Iran, Syria, Venezuela...Cuba all come to mind.) Americans have no special protections/human rights there and no rule-of-law or recourse if the govt decides to grab you off the street and charge you with anything they want, you are totally screwed!
So far we have been talking about what the american police state will do to you for going somewhere that everybody else can go to without problems.
Is it fair - no.
Is it right - hell no.
Is it the law - yes.
Is the law right - no.
If the law isn't right, is it right to overthrow the government - it depends, but probably not (but it did work back in 1776)
Michael