Well, and Microsoft seems to feel that their right to look at your system whenever they want trumps having any real system-level security to stop things like viruses. Any system has weaknesses, and sure, MS gets most of the malware action because they are the most popular platform. But they also persist in designing security flaws into their system, to benefit their own applications and to satisfy the demands of MPAA/RIAA and others, whereas Linux teams tend to eliminate security flaws as fast as they can find them. (I used to feel I could also cite Apple in that list, but their idiotic implementation of "widgets" or whatever they are called pretty much ruined my optimism toward them.) So in part it's the users who are most prone to let the bad stuff through, but in part it's also the OS most prone. My 2 yen, anyway.
