This may be news to some of you but I'm sure you are as aware as I am that MACs can get malware. If I had a pound for every time I'd heard someone say "Macs can't get viruses" I would be a very rich man indeed. If anyone ever tries to argue this point after you have told them they are wrong then below is just one of many articles you can point them towards.
The Mac-specific Flashback Trojan created a zombie army of 550,000 Mac machines by exploiting a Java hole that Apple only patched on Tuesday, six weeks after Microsoft plugged it up on Windows machines.Story @ The RegisterSinkhole analysis @ Dr. Web
This is according to Russian anti-virus firm Dr Web, which arrived at the figure after it successfully managed to sinkhole one of the command-and-control servers used to control Mac machines hit by the latest attack. The legions of compromised zombies were mostly located in the US (56.6 per cent, or 303,449 infected hosts), Canada (19.8 per cent, or 106,379 infected computers) and the UK (12.8 per cent or 68,577 cases of infection).