For years, Mac owners have laughed at the frantic efforts of their PC neighbors to fend off attack by viruses, Trojans, rootkits, and other malware. Given that PCs are a vastly greater segment of the market, it's cost-effective for the bad guys to concentrate on PC attacks. And yes, it's true that Apple's operating system is tougher to crack than Windows. But the days of Mac complacency may be ending. First, some threats are completely platform-independent. If a phishing email can fool you into entering your credit card data on a fraudulent site, it doesn't matter if you're running Windows, Mac OS, Linux, or DR-DOS. You're hosed.