The problem with that is it's simply not practical to expect all of your contacts – to say nothing of your grandparents – to do the same, which means that at least some of your emails are going to be exchanged in the clear. And as this fascinating Bloomberg report about the surveillance activities of the former Tunisian regime reveals, that creates another kind of vulnerability that concerns not only what you send, but also what you receive:

Asma Hedi Nairi, a former Amnesty International youth coordinator, says e-mails she and her friends exchanged were replaced by messages ranging from random symbols to ads for rental cars. Opponents of the regime toppled in January’s revolution received threatening messages such as “you can run but you can’t hide,” while people with no role in politics found their correspondence snagged if it inadvertently included words flagged as critical of the government. Ammar 404 even damaged reputations by inserting pornographic images in work e- mails and routing intimate photos onto Facebook, Nairi, 23, says.

What makes this story particularly disturbing is that practically all the technology used to carry out this disinformation campaign in Tunisia was provided by Western companies, who seemed to view it as a test run:

Western suppliers used the country as a testing ground. Moez Chakchouk, the post-revolution head of the Tunisian Internet Agency, says he’s discovered that the monitoring industry gave discounts to the government-controlled agency, known by its French acronym ATI, to gain access.

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"Tunisian state secretary Sami Zaoui just announced (mirror) that they will keep blocking websites that are "against decency, contain violent elements or incite to hate". When criticised that this is inacceptable in a democracy, he responded (mirror): "Wrong! Even the countries that are most evolved when it comes to freedom block terrorist sites"."

In the case of Tunisia, which just had a revolution or perhaps is still in the process of a revolution, it becomes immediately clear what the problem with such filtering is. Basically, the government is keeping a tool in place which has been used to silence critics in the past. Also, the conditions for which websites are censored are quite vague. Inciting hate and containing violent elements seem quite clear, but as we've seen in Turkey, such conditions can easily be stretched and that's without even taking the 'decency' condition into consideration.

Both the US and the EU are obviously failing to be a rolemodel when they should be. Many politicians in the EU have embraced the idea of an internet filter to block child pornography. As for the US, they could be seen seizing domain names of 'rogue websites'. On the one hand, politicians of the west love talking about the principles of freedom, but on the other hand they hate to actually live up to their own standards when something like WikiLeaks or a music blog comes along. The problems of this for the US and the EU have been discussed here in detail before.

What such censorship also does, is create a dangerous precedent, because it allows for repressive governments to create excuses for censorship. This is to be expected, and we've predicted similar things in the past. If Western countries are really serious about stopping internet censorship (and they're probably not that serious), they need to actually learn to live up to that ideal. Otherwise, we're going to see more and more state-supported censorship defended by the fact that Western nations are just as bad.