Rebecca Freed writes: "Are Macs impervious to malicious software? No. Have Macs been the subject of catastrophic attacks? No again. Should Mac users be vigilant anyway? Of course. The complacency about Mac security has some basis in fact: OS X comes with many of the ports that could allow snooping closed; you have to change a System Preference to activate file sharing, personal Web hosting, or even printer sharing. If you don't use these features, you're protected by default. If you want to give other users access to some areas of your system, you should turn on the firewall that's built into OS X."