They do realize that this could come to resemble Fascism, correct?.
As for blocking the Child Porn sites, that's great in theory, but in practice, it's not going to help that much, not only for the reasons stated, but because you can't stop an industry, however discreet and depraved, by blocking one stream of revenue, they'll find others.
What this really does, unfortunately, is open the door for other people to complain and begin censoring things they consider obscene.
On this fucked up little rock called earth, there do exist people who are crazy enough, ignorant enough, dishonest enough, and self centered enough, to state that Call of Duty is just as obscene as child molestation.
The general populace is stupid enough to believe them, and the governments are greedy enough to exploit their stupidity.
This isn't going to stop child pornography, all it's going to do is license the powers that be.