This guy made an amazing chart that shows you exactly what Google is asked to censor.
For the United States, by far the largest percentage of requests were due to "defamation" - which, really, is such a broad term that it could mean pretty much anything. Apparently only 1% of the requests were for government criticism, but you have to wonder if individual government officials would fit under the "defamation" category. Or perhaps I'm too suspicious?
Interestingly, there is no record of the compliance rate as measured by reason for request.
As more and more hours of more and more people's lives move online, we've begun to shape the online space in fascinating ways. A large number of people with the time and inclination to be online are middle-to-upper-class people in the 15-55 age bracket. We've moved from a relatively anonymous, sparse landscape to a place where we all post pictures and invite other people into our lives with blogs and Twitter and Facebook. There's internet memes and internetspeak that only the initiated are privy to (ALL THE THINGS!).
The internet was created to spread information, and you'll notice that people on the internet are incredibly willing to help one another - whether it's digging up relevant medieval sources, or patiently explaining to some knucklehead on Yahoo!Questions that no, Russia is not invading the state of Georgia. But on the other hand, we've brought our prejudices with us to some extent as well - girl gamers are very aware of the welcome they'll receive from their male compatriots online.
Up until very recent times, the internet has been largely unregulated in many places. It's very hard to enforce laws about, for instance, online harassment or threats, or the involuntary spread of personal information. That can be harmful, but on the other hand, it's also difficult to enforce sometimes arbitrary rules about age or background or what have you. For better or worse, the internet is our sandbox, to remake in our image like the egomaniacal little gods we all are.
But now things are changing. Monopolies have been built - the best known, of course, is Google. They don't want to be evil, but it's pretty hard to say no to your overlords when you're making so darn much money. We can see The Powers That Be moving in and attempting to shape the way the online world looks.
We'll see how things look ten years from now.