Cuddle a Mac. It’s clean, for now

TBWA’s latest onslaught of Mac advertising in the UK includes this oddly-worded poster seen on the London Underground. It’s slightly misleading because it implies that there are no Mac viruses. In fact what it's really saying is that there were not 114,000 viruses for the Mac - a different claim altogether.
It’s true that the cuddly Mac is certainly more immune to such attack than is the PC, but it is still vulnerable.
Although I can’t imagine why anyone would want to do this, there have been cases recorded of Macs with Windows operating systems being hit. Macs have also been targeted by Trojan Horses (not technically viruses).
I find this focus on the Mac's better security slightly ironic. The main reason for its good security record is that virus writers can't be bothered. Were the Mac to increase its market share (it’s currently something like 5% compared to the various PC brands in the US), then virus creators just might regard Apple as a worthwhile target.