Software vendor CA recently took me for a tour around their AV research centre in Melbourne, where I got to visit their "live virus" room, which was the only place in the building I saw a Mac.
CA's office includes one of the largest antivirus research labs in the southern hemisphere. Part of that is a little room that contains numerous filing cabinets stuffed full of 5.25-inch and 3.5-inch disks, each of which contains a "live virus".
In the corner of this room was the only Mac I had seen in the building.
I mentioned this to our tour guide -- CA's VP of development Eugene Dozortsev -- who, as you can see in this video, said: "Actually, the Mac is as vulnerable as everything else ... Don't make any false assumptions that there are no viruses on Mac. A lot of things like Trojans and e-mail worms [affect the Mac] the same as they would in the PC world."
As irrational as it may be, I know I would feel much safer running OS X in that room.
What else would you load on to a computer when you knew it lived in the same room as a few hundred thousand viruses?
It was very strange looking at so many disks, each containing the work of an early malware author. Of course the disks are no longer used -- Dozortsev called it "memorabilia" because modern threats are stored on a "dirty network" that is run through the research facility.
I wish I had asked which OS they use when plugging into that network!
To see a short video tour of the live virus room, click here: CA virus room tour.