From BBC News:
On the eve of the 20th anniversary of the Tiananmen killings, social networking sites such as Twitter and the photo-sharing site Flickr were blocked in China in an attempt by the government to prevent online discussion on the subject.
But Chinese twitterers proved that there are ways to get round the great firewall of China.
Frequent twittering from users in China has contributed to Tiananmen becoming one of Twitter’s most discussed topics during the anniversary.
One twitterer wrote: “I cried when I watched a video about 4 June 1989. All my memory came back. We are living inside a big wall, like in prison.”
Read also Web Blackout Fades in China by Sky Canaves.