Hong Kong and Macau are special administrative regions (SAR). For all intents and purposes, they are independent from China except for two key aspects: military and foreign affairs. They have their own courts, their own law, their own police, their own currency, their own visas, etc, etc, etc. It's known as "one country two systems".

The occupy wall street people in Hong Kong are actually camped INSIDE the HSBC HQ building (granted, it's a special open-ground-floor building). But the sense that you get from HK is one of more freedom than the west, not less.

They still have a (somewhat) separate judicial system and government, which results in a considerably freer media and society; for example, many of the newspapers print anti-PRC editorials that wouldn't be allowed in mainland China, and there are open demonstrations on things like the Tiananmen anniversary.

The Hong Kong Basic Law stipulates that it will have high degree of autonomy at least 50 years after its transfer to Chinese rule. (ref http://en.wikipedia.org/wiki/Hong_Kong)

The Hong Kong Telecommunity Authority is, therefore, not required to implement the GFW.

Even in China, there are some GFW-free spots. You might find some 5-star hotels giving you unrestricted access to the likes of Facebook, Google+ etc