580 people attended a conference on spam (well, on stopping it actually - it was not an email marketing conference). That's quite a number.

Among the speakers was a Microsoft researcher - Joshua Goodman (Warning: PowerPoint at end of link). Among his points was one of those lines you've been hearing a lot about a almost anything - namely that open source software helps evil spammers learn how to get past anti-spam filters. To his credit, he knows people will attack this point, but one has to wonder, if they teach you to say this in Microsoft School or is it just something PowerPoint inserts automatically when it sees the words open source?

No empirical evidence shows open source anything to be more vulnerable to security threats.

As to gold standard spam filters (like SpamAssasin) being the thing to beat: A gold standard is the thing to beat no matter whether it is open source or not. With spam it is very simple. Keep writing spam until you're not filtered.

Spam filtering seems to be the latest craze for computer scientists looking for interesting jobs. You get to apply classical CS and a little math. There's plenty of test material to train on. The only drawback to this jop option is that the available free solutions are already very good - but of course for another year or so, not everybody will know this....

And what did I mean exactly with the "hearing a lot" quip above: It seems in this economic crisis post 911 world that people find the argument "Freedom X also applies to malicious agent Y leading to consequence Z - therefore freedom X is bad" compelling regardless of what X, Y and Z is. The opposite is true of course. It takes very particular qualification of X,Y and Z to make the statement true.