This thread reminds me of a really thought-provoking TED talk in which the speaker made interesting comparisons between censorship and the way Google (and other internet companies) creates "filter bubbles" through its use of algorithms to filter search results based on what it thinks will be relevant to you. It's pretty scary, especially if you aren't aware that it's happening.
The video is about 10 minutes long - I encourage you to check it out!
Eli Pariser: Beware online "filter bubbles" | Video on TED.com