I was a teenager in the days before the 'net and somehow we still managed to get hold of !$%*! and lots of it. To think that censoring the net will stop kids getting hold of !$%* is even more naive than Dilbert thinking he can outsmart a savvy net kid!
Here in Czechia we have no such censorship, people have better things to care for. I think only Vodafone implemented somethinkg like that, but the company got severe bashing for it :)