So I was poking around the net today while watching the Michigan -v- OSU game and found this article rather interesting...
*snip*
There are about 60,000 viruses known for Windows, about 5 for commercial Unix versions, and perhaps 40 for Linux.
*snip snip*
None of the Unix or Linux viruses became widespread - most were confined to the laboratory.
Link:
Linux vs. Windows Viruses | The Register