User ID: a police officer checks registrations at an internet café in Xuchang, central China. From next month, Beijing wants new computers to be installed with extra controls

This week, an open letter appeared on Chinese blogs and online bulletin boards. “Hello, internet censorship institutions of the Chinese government,” it said. “We are the anonymous netizens. We hereby decide that from July 1 2009, we will start a full-scale global attack on all censorship systems you control.”