The Australian government is currently running a mandatory content-filtering trial in order to block child pornography and other content that is considered "improper". The filtering or "clean feed" is based on the Australian Communications and Media Authority's (ACMA) blacklist which contains addresses to websites that are prohibited.

I touched on the subject of content filtering in the whitepaper "ISP Level Malware Filtering - An Extended Clean Feed?" where I found that some ISPs, such as Internode in Australia, would like to focus on malware filtering rather than performing questionable filtering on "improper" Web content - filtering that could be argued to represent a form of Internet censorship. According to the Sydney Morning Herald article "iiNet pulls out of net censorship trials" another Australian ISP - iiNet - has not only spoken out on the issue, it has decided to withdraw from the Internet censorship trials.

The ACMA blacklist that is used as a backbone for the filtering leaked on to the Internet - as reported by Wikileaks.org (a website publishing anonymous submissions and leaks of sensitive information) - and the "secret" list of banned sites was revealed. The leaked blacklist was, however, about double the size of ACMA's list, a fact that was used by the Australian Communications Minister, Senator Stephen Conroy, in order to discredit Wikileaks. The leaked list's large diff in extent was then explained by Wikileaks, stating that the first leaked list was from August last year and that list contained several URLs that already have been removed by ACMA. Wikileaks, however, quickly leaked another version of the blacklist - from March 18, 2009 - along with instructions for authenticity verification.

Michael Malone, the managing director of the Australian ISP iiNet, states that,

"We are not able to reconcile participation in the trial with our corporate social responsibility, our customer service objectives and our public position on censorship," and "It became increasingly clear that the trial was not simply about restricting child pornography or other such illegal material, but a much wider range of issues including what the Government simply describes as 'unwanted material' without an explanation of what that includes."

In the whitepaper "Enter the Dragon - Exploring the Internet Networking Context of China", I expressed my concern that the strong censorship of the Chinese government may impair people's freedom in their digital living space. It is easy to understand the objective of a certain amount of content filtering - such as filtering content related to child pornography - but such (and all) types of content filtering has to always be done in a balanced way.

Sweden adopted Internet content filtering of child pornography related content in mid 2005. The Swedish company NetClean develops technical solutions for the blocking of child pornography related content. The NetClean Whitebox solution, to use one example, is used by New Zealand ISPs in order to block addresses that carry illegal content. The Watchdog Corporation Limited, situated in Auckland, New Zealand, is stated to be one of NetClean's international business partners. TeliaSonera, which is the largest telecom operator in the Nordic and Baltic countries, is stated to be one of NetClean's industrial partners. The Swedish ISP TeliaSonera installed NetClean's filtering solution in their entire corporate network in 2006. NetClean also collaborates with several law enforcement authorities around the world.

There are ways to filter illegal content - such as child pornography related content - in an intelligent manner, minimizing the filtering of false positives. The content filtering trials in Australia has, however, taken an extended route. The delicate balancing act of "clean feed" becomes far more difficult and questionable when extending the filtering to also encompass other so-called "improper" content. Doing so may tip the scales of a balance towards Internet censorship.

LS Pekka

Lavasoft Malware Labs