The fact is, Unix-based OSs are just inherently more secure than Windows. I’ve read countless articles describing why Windows was so badly designed, even at its foundations, that viruses can run rampant. Things like blurring the edges between adminisrator and user rights, permissions being non-existent or badly configured, etc. – things that just don’t happen on Mac OS X or any other Unix flavour.

Sure, no OS is bulletproof. Users must be vigilant, regardless. There’s no room for complacency. Generally, I know that if I practice good Internet and file security, put myself behind one or more firewalls (I do), etc. then I will be generally safe – but I am not foolish enough to just say “I’m on a Mac, I’m immune to attack”.