It might be illegal, but nobody knows it; everybody who wants one will probably just get one (I used to live in China). Not that I agree one iota with it, but I can definitely understand the government's need to control thoughts: it's lead to great stable economic development so far; they operate in what has always been the prevailing mode of government throughout history; they have a different idea of morality (one that's not necessarily wrong) - that the individual rights are weighed much more lightly compared with the greater societal good. In addition, though not overtly, our media is also structured in such a way that they passively try to control our thoughts.