Your Mac's biggest threat: You
I'm being asked more and more by Mac owners if they need to worry about viruses now and do they need to install virus checking software on their mac. You can read my answer in this blog post.
What prompted me to write this blog entry was an article at GigaOm.com about the ways "Bad Guys" can attack your computer. Not via the Internet or by infected software, but by phone. By speaking to you and convincing you there is a problem.
I've received one of these calls myself and it brought home the fact that these people really do exist and they really do call you and try to convince you that there is something wrong with your computer and "they are here to help."
So read this piece by GigaOm. If your parents have a computer (Mac or PC) tell them to read it too.
And if you ever get called by these thieving parasites, collect as much information as you can and report it to the ACCC's ScamWatch here. Or call them on 1300 795 995.