[wisty]

They tried this in Australia, some time ago.

The PM told the minister to do it. The minister (who's reasonably tech savvy) told the department. The department told him it was a joke - it wouldn't work, and the government would get blamed every time a legitimate site was blocked, or a kid got caught bypassing it.

It's political suicide. They will be blamed every time a teenage boy figures out how to bypass the filter (hint - they all will). They will be blamed every time they block a non-porn site. Tech sites will publish "10 ways to bypass the government's joke of a filter" articles. Current affairs programs will have concerned parents shocked that their unsupervised 14yo boy filled their computer with smut (probably passed around on a USB). The next time an MP or celebrity gets arrested for really shady stuff, they'll say the filter failed. They will look like idiots, and waste millions doing it.