Hands up all you Mac owners who don't run any antivirus software on your computer? Thought so. The message that's been drip-fed to Mac users, and is now self-perpetuating, is that Windows PCs get viruses while Mac users don't. Leaving aside the self-righteousness issue, it's fair to say that there are currently a lot less viruses for the Mac, partly because it hasn't been such a big target (Windows variants take around 90% of the operating system market) and also because it is built on a more solid, but not invincible, framework...