One of the advantages of having a centrally controlled internet is that you can switch it off if life gets a bit tricky.
It is looking like that is exactly what the Chinese government did yesterday when it became concerned that some citizens might remember the importance of the date - the 24th anniversary of the massacre of protesters in Beijing's Tiananmen Square.
China has decided that the best way to commemorate the massacre is by declaring 4 June "internet maintenance day" when all loyal communists spend the day updating their servers while remaining unconnected to the net.
To help the loyal network managers, the government switched off the internet so that they were not bothered by too much net traffic.
Of course, you can't shut off the entire internet, so some extra special sites were told to commemorate internet maintenance day while others had to bite the bullet and update their servers in the normal manner.
Those sites under maintenance include blogs and websites that might want to remember 4 June for reasons other than being a patch Tuesday.
According to the Washington Post, a picture which edited the iconic image of a man standing in front of a column of tanks by replacing them with rubber ducks was also censored.