As far as predicting the market share at which Macs get malware, Adam J O'Donnell seems to have given a 5 to 10% of the Internet population estimate in this pre

As far as predicting the market share at which Macs get malware, Adam J O'Donnell seems to have given a 5 to 10% of the Internet population estimate in this presentation: http://projects.csail.mit.edu/spamconf/SC2008/Odonnell_gametheory/odonnell-gametheory.pdf http://projects.csail.mit.edu/spamconf/SC2008/Odonnell_gamet..., with a more cautious paper here: http://www.securitymetrics.org/content/attach/Metricon3.0/j3attAO.pdf http://www.securitymetrics.org/content/attach/Metricon3.0/j3... That presentation dates from 2008, it looks like, and O'Donnell gives both Mac and Linux a 4% market share at the time, which seems a little suspicious in that almost everyone else gives Linux just barely 1% even now.