This won't actually get up. Bob Carr suggested something similar in the 1990s and it just never happened. Sure, it's technically possible, but it'll be pointless. So they block a site on [say] how to build your own atomic bomb. The thing would just get mirrored. ASCII text is replaced by a GIF of the same text, so the 3 guys scouring the net for "bad" content will take months if not years to find it.
This is as much pie in the sky as the RIAA's attempts at stopping illegal downloading. Site will move and content will get around the system. And the idiots dumb enough to handle Plutonium in their backyard shed will develop acute radiation poisioning either way
