With the erosion in Windows' market share and the increased use of Macs, it was a matter of time before Macs became a target for malware. Based on what happened with Windows and its base of "gullible" users, can't say that one couldn't see this coming. Apple will have to take a close look at securing the desktop against threats that play on their users's lack of sophistication when it comes to computers. It will be interesting to see whether they choose to go the Windows way with more warning boxes and lower ease of use, or find a different way.