They're as secure as Windows 98, the reason why they're "immune" to viruses is NOBODY CARES to make one. Sure you can go buy the Mac version of a game, but they aren't always released for Mac and nowhere near as much in stock as a PC. Sure Microsoft has more viruses, only because they have a higher number of users making them a WAY bigger target. The only thing a Mac is good for is computer illiterates. PC wins!