I have to say that every time I've been back to China, I've encountered absolutely nothing in terms of enforcement of laws regarding security, information, freedom, religion, porn, blah blah blah. The real problem is the latency of the connection from China to the US. It is absolutely horrible.

I was recently in Shanghai visiting family and took a lot of photos and would upload them to Flickr through the Flickr Uploader software. Typically, I would have to try 3 or 4 times to get them uploaded because the connection would keep timing out. Same thing for accessing my bank account, my credit card, and so on. Incredibly slow because of the latency even though I was on a 1.5Mbps/256Kbps DSL line. I also had no trouble getting to major US newspapers like the NYTimes and CNN, and no trouble getting to porn sites in the US. Mind you, this is all on a connection provided by, and available only through China Telecom, a corporation that is state-owned and operated (They own and operate all phone communications in China I believe).

So for those people who are moving to US and are deathly afraid of loss of such freedoms, don't be, as others have said, as long as you're not trying to raise a ruckus, no one's gonna give a damn. Though being guarded about your opinions in front of people in high positions of power maybe a worthwhile tactic. I would guarantee you, in most places, people will eye your skin color and then think about how to make money off of you first before they worry about if you're gonna try to spread the evils of western-style thinking. What you should be most concerned about is the difference in manner and attitudes of Chinese people.