It's only business, and it's called fear tactics. Symantec wants to sell more products, and with OS X, especially Tiger, they are loosing business, so they come up with a "Study" and plays on their customers fears. It's widespread in marketing, advertising and sales. The fact is when was the last time you heard of a widespread Mac computer virus? Not to say it can not happen, but until microsoft switch to the mac platform...probably won't.