I think the other important point is that censorship of the net like this isn't something that will stop people visiting websites. It's easy enough to just get the content another way.
So the censorship will have pretty much no effect, apart from negative PR.
I suspect that we're talking about some old people here.. legislators who have literally no idea what they are attempting to regulate, or it's potential consequences.
A mechanism like this get's implemented under false pretenses ("do this and it will end child porn forever") - then it becomes a future tool to abuse individual freedoms.
So the censorship will have pretty much no effect, apart from negative PR.