Actually, the best way to fight piracy is to make a product pirates aren't interested in.
Yes, but if you can't communicate your results, what good are they to the rest of us?
I voted for communication because the state of science journalism compelled me to.
While market share might be a factor (infact almost definitely IS a factor) in the security of Windows vs OS X/Linux, IE vs Firefox, etc, it's more likely the architecture.
The architecture of Unix systems (running as root, user permissions, etc) makes/made it very hard for malware to be written for it. At least, to cause any significant damage.
Though in the case of Firefox vs IE, I'm not so sure. I know little about either browser's architecture. But it might not be just market share that's the reason for the huge number of sploits for IE as opposed to firefox.
When in doubt, mumble; when in trouble, delegate; when in charge, ponder. -- James H. Boren