You raise a good point, and it is quite probable that our freedom of speech in in democratic countries may be compromised. From the little I know , people can easily get into your face and call you out about the war effort going on over in Iraq depending on how who you talk to in America.
But strangely enough there HAVE been censorship incidents in North America. The internet provider AOL censor the word "breast" from it search engines - nothing would come up -- which not only stupid but it also hindered the breast cancer campaign. Also I heard that google changed it's "safety" settings that the word clitoris (or was it vagina,? I can't remember) would only sned back results on the lowest setting, but they didn't adjust the setting for the word "penis" at all. Apparently you can't get anything dirty with that word. /sarcasm
Also, CNN may not censor it's findings to my awareness but it has a history of being one-sided, or presenting it's finding in a not so nice and bigoted way.
But the scary question is if censorship was to occur in a democratic country, would it's citizens even know it, or they would they disbelieve it because some piece of paper states they have rights and freedoms.
Speaking of rights and freedoms -- the Chinese government that by providing literacy and closing the distance between the rich and the poor they are giving one Freedom so they can constrict any other Freedoms because the cause creating everyone equal is more important.