China (the nation) has responsibility for over 1.4 billion people. Net storms through inuendo, false information, etc are easy to incite (similar to inciting a riot in the USA). People are easily mislead (example - the recent 21 May "rapture" prediction).
Foreign websites, news agencies, commercial sites (google, facebook, etc) while having many social and commercial benefits, refuse to submit to domestic government controls, thus permitting porn, frauds, prostitution, gambling, drug dealing, etc - all kinds of crimes unleashed on the public.
The west calls it censorship, China calls it responsible business operations with the necessary forensics to track down criminals. Dissidents and their supporters are selfish self-delusional criminals. They have zero responsibility for the welfare of the masses - actively promoting their personal agendas of change in a society already afflicted with massive cultural upheavals - creating massive income gaps between the majority rural population and the more affluent municipalities, leading naturally to social instability.
The internet can be painful for we expats - but that's one of the costs of living in one of the world's most populous and powerful nations.
WIFI COLLISIONS
Bluntly - I've seen the internet slow down, speed up also - I've also noticed the number if wifi routers in my neighborhood increase from 2-3 (including mine) over the last couple of years to 8 or more just in my neighborhood. Yet another potential source of dropped connections are DNS pre-fetch (it's automatically configured in most OS's and must be manually disabled, and of course the current topic - WIFI noise or traffic collisions.
Some lite tech stuff about wifi - 5-6 of my neighbors are all transmitting on channel 6 - making for a miserable wifi connection experience. If you're having difficulties - use wifi snoop software (osx use istumbler) to snoop the wifi noise in your neighborhood - then manually change your wifi channel to something less populated - eg channels 1-3 or 8-13) - and make sure you've activated WPA/WPA2 encryption.
FYI encryption slows down your internet (adding a send/receive encryption layer) - but dramatically reduces casual clear air interception of your traffic (aka sniffing).
Simple tools such as PING, <traceroute>, and the PING Sweep help diagnose your local network issues - providing info on how many users are sharing your IP segment, how many bounces your traffic takes within your ISP before it makes it to the info highway, etc.
China really could care less about our expat web surfing, as long as we don't create problems (eg DL and distribution of porn, online gambling, and other general nuisance making things - they are incredibly interested in domestic traffic and ensuring irresponsible individuals and or groups don't create firestorms, ensnaring the gullible etc.
The government recently announced the formal creation of a ministry to manage internet content - so expect to see more painful activities in the near future, as they flex their newfound muscles.