w3rd!!! I completely agree with this sentiment.
For one, if the internet were to be censored or its content otherwise "monitored" by some government-placed agency (ala Homeland Security), exactly what type of limits would their power have? And what would stop them from taking all sorts of other liberties / changing their scope in mid-stream?
And, since the internet is NOT a US-controled entity / communications avenue (hence WORLD-wide web) I seriously doubt all, if any, other countries would agree to censorship governed by the US. I mean, a good portion of what is deemed inappropriate on the web is regular, everyday TV advertisements from Europe, etc.
All in all, like every other form of censorship IMO, this should be the role of the parents. And no one else.