A friend of mine (and his girlfriend) went to teach English in China for a year and while their blogged about their experience. They had had their blog before they even thought about doing this and when they were not trying to hide anything, but the blog site they used was blocked for citizens of China. Well, turns out someone at the school  where they taught contacted a friend who worked in their embassy in Canada and had them print out their blog and fax it back them. My friend found out about this when the school accused them of spreading lies about the school. They ended up cutting their year short and basically fled the country because the school was threatening to have them arrested.