Spam - it's a bad thing. So far, so uncontentious.

The volume of spam that people are receiving these days is such that many are using automated tools to filter it out. Many of the state-of-the-art use Bayesian Filtering to decide if something is spam or not. SpamBayes seems to be one of the most successful at the moment.

In Bayesian Dark Side, Ian Bicking raises an important issue which hadn't occurred to me. An oppressive government could use this technology to control its citizens' access to the 'net. The better spam filters become, the more effective they might be as censorware. And they are getting very good indeed, given the Red Queen style arms race that the spammers and the spam tool writers are engaged in.