Prisoners in jail, in my country, or every other country you can imagine, can't leave either. It's called conviction. China invented a lot of things, but surely not this.
Precisely my point - you were making a false (in?)equivalence by trying to say that xinniethepooh's point was invalid because they were able to leave China while prisoners in Nazi Germany could not - while it's pretty clear that they weren't a prisoner in China, just a traveler.
