[DanBC]

Maybe you don't remember the root-kitted Redhat boxes in Korea which were, for some years, responsible for a surprising volume of spam.

Linux distributions then started shipping with un-needed services turned off, and increased broadband meant home machines were attractive targets for botnet malware.

In the past anti-virus on Linux tended to be used by people with a Linux mail server and MS Windows clients.

But, to bring it back to this particular discussion: It'd be fairly easy to wrap malware around a Mac OS X software. The user would need to click and give it permission to install. But how many Mac users run as admin and would just click the warning anyway?