In 1977, a group of Czech intellectuals irritated the then communist Czech government by producing a document called the Charter 77, which demanded human rights and democracy, and lambasted the Czech government for denying its promises in this regard. Though the Czech government lashed out, ultimately the demands outlined in Charter 77 were upheld after the fall of communism. Liu Xiaobo and a large number of other Chinese intellectuals were inspired by this document, and made a similar one called Charter 08 (as it was written in 2008).
This clearly annoyed the Chinese government, who not only was very irritated to be criticized like that, but also considers human rights to be a load of western bullshit that would derail Mao's vision of an equal society. Mr. Liu then went on to further annoy them:
(It would take) 300 years of colonialism. In 100 years of colonialism, Hong Kong has changed to what we see today. With China being so big, of course it would require 300 years as a colony for it to be able to transform into how Hong Kong is today. I have my doubts as to whether 300 years would be enough.These kinds of views are generally seen as seditious, and I think if I expressed any similar beliefs (if I advocated that it would be a good thing if America were to be conquered by another country, say Germany or China), I think I would be loudly denounced as a treasonous bastard, though not arrested. The Chinese government, nationalistically insulted, arrested Mr. Liu on grounds of sedition.
The Chinese government was further enraged when Mr. Liu was awarded the Nobel peace prize for the work on Charter 08, and its inability to lobby the Norwegian Government to influence the decision. (Members of the selection committee are chosen by the Norwegian parliament, but the government has no further input on selection and certainly enjoys nothing remotely similar to veto power.)
So that's why he's imprisoned, why the Chinese government is mad at Norway, and why shit will fly for years to come from all this. I argue that human rights, "Ren Quan" in Chinese, is an important part of Sun Yat Sen's "Minquan," or "people's power."