No, of course not. However, it isn't an excuse for censorship. It is an excuse for going after the people producing it, and monitoring those who consume it (in the USA, the FBI is the largest distributor of child porn, with the goal of arresting people who look at it, for instance). Also, there's a pretty huge difference between censoring all the pornography on the internet (which would inevitably include lots of non-pornographic content) and occasionally asking hosting companies to remove illegal content from their networks as part of legal action against the offending individuals.
Also, as an aside, I find it interesting that child porn tends to crop up in every single discussion of censoring the internet. It's something that pretty much everyone agrees is wrong, true, but it's not an argument for generalized censorship, any more than the existence of child abuse is an argument for putting sensors on every child in the world to see if they're being abused.