Every time I write about Windows security software, I get a predictable flood of responses from Linux advocates who claim that they don’t need any such protection. Today comes a shining example of why they’re wrong.Linux infection proves Windows malware monopoly is over; Gentoo ships backdoor? [updated] | ZDNet
Linux and Apple are not more secure by nature, they are just smaller targets for virus producers. I remember once I read a Apple users on Flickr advice group telling people on Macs they don't have to worry about viruses. I have had viruses on several Mac machines over the years, and I have anti-virus on my Linux boxes. These systems unsecured are still unsecured and the only protection you get with them is that few malware developers would waste their time on a system that might get a few hundred thousand users globally.