The Open Net Initiative has announced an increase of government online surveillance. From only 2 governments filtering content in 2002, they have found evidence of state-mandated net filterning in 25 countries out of 41 surveyed. The reasons cited in the BBC article are politics and power, security concerns and social norms.
I agree that there is a lot of dubious material on the net, some of it in bad taste, some of it maybe even dangerous. But I object to somebody else telling me what I can and cannot read. The worrying part of this expanding government control of cyberspace is that this is just a step away from limiting freedom of speech.