Windows users, or at least those who are technically inclined, like to keep their systems locked up like Fort Knox. I know my Windows desktop is. Mac and Linux users don't really have this issue. Why is that exactly? Macworld has an interesting article on the subject as to why Windows has a much higher infection rate than OS X, and why Macs don't really need anti-virus software at all. It's not because Mac and Linux systems are necessarily more secure (or that Windows is less secure) but rather because of their install base. Security expert Bruce Schneier noted that the magic number is 16%. That's how much of a market share an OS must have before writing viruses and other malware for it becomes profitable.

The article notes a changing trend in the way malicious hackers and other cyber crooks are doing business. Phishing is becoming more popular than viruses. That's presumable because phishing scames can be set up faster with less effort, especially concerning the recent issues with the way the web fundamentally handles web addresses. According to Macworld, this is the biggest threat to all computer users. The problem with Mac is that Safari does not currently include built in anti-phishing software, compared to Mac versions of Firefox and Opera which do. Stealing your identity is a lot more lucrative than vandalizing people's computers and phishing is easier than using complex key loggers and other spyware. If you use a Mac, don't bother with anti-virus, switch your web browser.

Source: Macworld