Technical reasons against the Clean Feed

From Ars Technica:

Here's an idea: if the Australian government actually finds child porn, nuclear bomb making manuals, and the like on the Internet, why not do their best to find the perpetrators and put them behind bars? That way we get to keep our free speech and have less crime and terrorism, rather than less of the former without actually reducing the latter. Then again, imposing restrictions on what local taxpayers can do is a lot easier than tracking down and rounding up international criminals and terrorists, and the filtering plan is moving forward despite the massive and fairly obvious drawbacks.