The Rudd-Conroy national plan to filter the Australian Internet, according to the Australian Computer Society

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The Australian Computer Society (ACS) has just released a report on the Rudd-Conroy plan to censor the Australian Internet aka plan to implement a mandatory national ISP-level Internet filtering scheme.

Now it's no secret that ACS was and is generally in favour of the Rudd-Conroy plan, but even it felt compelled to point out the following blindingly obvious.

There are a number of issues that need to be addressed when it comes to the implementation of ISP based filtering, including:

• sites can easily be renamed and so the names will not match the black or white list;

• language translation (often automated) often produces mistakes and so international sites may not be filtered effectively;

• lists must contain domain names as well as IP addresses to be highly effective;

• not all applications work well with a proxy server and so the performance of the ISP can degrade;

• push technologies (such as RSS) often bypass the proxy server and deliver content directly to the user so circumventing the filtering process;

• not all users access the Internet via an ISP;

• many sites have mirrors and multiple URLs and if these are not included in the black list then the filtering process can be circumvented; and

• proxies can degrade ISP performance particularly during periods of high traffic – they become bottlenecks and can reduce Internet speeds;

• mandating or architecting a network so that all packets pass by a filtering point can create performance problems, duplicated traffic paths and may increase the bandwidth costs for ISPs.

The report also canvasses the real possibility of overblocking sites such as Wikipedia, Facebook, MySpace, Blogger, and any other hosting site where users share the same basic URL.

The full ACS 2009 report with a few handy hints concerning methods of circumventing ISP-level filtering: TECHNICAL OBSERVATIONS ON ISP BASED FILTERING OF THE INTERNET.