In anticipation of possible protests in memory of the Tiananmen Square massacre 25 years ago, China has blocked access to Google search and Gmail. The censorship has been in place for a few days now, suggesting that this may be more than a short term action.
China has long blocked access to YouTube, Twitter, Facebook, and services which would circumvent the blocking, like Anonymizer.
Google search, and Gmail are both popular in China. It will be interesting to see if this actually draws attention to the anniversary, rather than diffusing it.
The image with this post is from 2010 when Google moved out of their China offices to avoid government control. (via Wikipedia)