[tag]Search engines[/tag] have been in the news lately for their preference to filter their results to please the [tag]Chinese[/tag] government.
I don’t want to go into that discussion again.
I want to point you to a nice project by Mark Meiss and Fillippo Menczer from the University of Indiana School of [tag]Informatics[/tag].

They have created a search tool where users can compare search results for Google and Yahoo in different countries.
One of these countries is .. well yeah, [tag]China[/tag], and to see the difference of reality, type in the name of a certain square and you’ll see what I mean.
Check out Censearship
A Ni Hao to Seomoz where I read this first.