I think the parent is suggesting that a fact based criticism of China is difficult to perform in China.

This claim is actually a much more complicated one than the parent suggests. While it is true that a number of search terms are going to raise eyebrows in China (https://en.wikipedia.org/wiki/List_of_blacklisted_keywords_i...) the 'blacklisting' is a much more complicated algorithm than post-and-you-are-disappeared - for the most part there are filters for how large an audience certain messages can reach although on some platforms 'errors' will prevent certain words from being posted. (Anecdotally, I have encountered such 'errors' in America on Facebook while posting news about Occupy, leaked Trans Pacific Partnership documents, Snowden Documents, Wikileaks links, Manning documents and others. Facebook assures me that it's the spam filter - this never made logical sense to me but alas a tangent). Another complication is that much of the blocked content in China is foreign propaganda - if you look at the dissident news section of the Wiki article and follow up on them you will see that they are not grassroots news organizations but set up by Western states and notably America. This is a well known favorite tactic of the United States (see the use of militarized media in the invasion of Iraq, the Lincohn group infiltrations, Radio Free Iraq, Voice of America, the compelled press released by Iraqi bloggers detained while passing American checkpoints, etc - or look at the Cuban Twitter effort to overthrow Cuba this year - or look at the DARPA programs to use Twitter to 'deradicalize the Middle East', where they go so far as to use brain scans of people reading Twitter messages to predict which propaganda items will have the most positive US political impacts in Jordan, Egypt, Syria and others). A further complication is that America is under some of the same propagandizing efforts today and has asked a number of ways for authorization to interfere (it is not really known what is currently done without explicit authorization to combat these messages). Also, as mentioned in the 'sister comment', highly critical commentary is regularly and freely posted about the Chinese government. This is confirmed by both speaking with Chinese citizens and by Western studies of Chinese media.

Finally, I encounter this criticism fairly often. I actually agree in moderate doses with it. There are certainly states which a person would not get away with any sort of criticism of the government and there are states where all records of history are destroyed and rewritten as favored by whichever administration (both historically and today) - I do think to the degree that the United States allows most select information to become public and to the degree that the United States minimally alters records it should be commended.

Yet these freedoms are not worth anything if they are not practiced - it is important not to buy into the myths of our nation (well, my nation, I don't know where the reader resides) and to demand ever more of it and of ourselves.

And we must be careful here of the comparison - we do not want to suggest that the United States is somehow in every way more free than China. China is landing very softly into a modern Republican Capitalism, it's civil rights have been steadily increasing, and the China censorship bit is drastically overemphasized. As a last thought, the point the parent makes is tangential to the discussion at large, which is about Fourth Estate and penal system.