"[W]e regularly receive requests from government agencies around the world to remove content from our services, or provide information about users of our services and products," says Google, which has now released data on where those requests come from.

The answers may surprise you. Brazil and the US are high on the list, for example, but China is not. Some explanations here: Google's Orkut social net service is popular in Brazil, leading to many take-down requests, while China keeps its censorship data to itself.

Sam Greengard touches on the same subject in this slideshow, and addresses another angle in this blog post, Censorship as Business Strategy.