Salam
Yes, there is good and bad - the problem is all the exceptions. For instance, I am in Kuwait and a lot of health websites get blocked (inadvertently, I hope) because of individual words (try having students research fund raisers for breast cancer research and there are quite a few sites blocked).
True immoral websites (the naughty sex ones) should be blocked, but I don't believe that asking for the freedom of speech (which is what many people try to hail with regard to some of the crap) includes nasty pictures & sites. I feel everyone should be able to criticize their own government (this is illegal in Kuwait - you will be arrested for speaking publically against the leaders) and ask for changes in an appropriate manner. I feel that everyone should be able to speak their opinion on many topics, religion included. But I don't believe that saying/posting pictures of anything at all that comes to your mind, is what the whole idea of freedom of speech means (the whole, you can't cry FIRE in a crowded theater idea).
I think parents should be the first and biggest censor for children, but that they should educate their children WHY they are censoring some items. When you make something totally forbidden without explaining why, that makes it more enticing for kids to look for things, to check them out. Then when they understand (if parents educated them well), the problems will be less when they grow and can see for themselves that some of the crap on the internet belongs to a deviant portion of society that they do not wish to be associated with.
My 2 cents
Lana