Then, why do we have courts, armies and the police force in real life?
I would say censoring is a form of policing.
Lets be honest here. Does Pornography hurt you or me ? No. It is a vile, disgusting thing, but if a person sits down and watches it he is causing no harm to me.
It may be morally wrong but constitutes no harm to me, so why should I care.
I agree you may want to protect your children/youngsters of the next generation. Then go out and buy a program that blocks such sites.
Once you begin policing the internet you encroach on the freedom of expression of an individual.
Take China for example. Do you know what happened after the Tienanmen Square riots ? Hundreds of students were publicly executed.
Till today, if you type in the word Tienanmen Square into Google in China you will see a blocked page.
Policing the internet may bring about certain benefits (I wont disagree with that) but its potential for misuse is far greater.