As a long time Linux user, I always more or less assumed that I was safe from viruses. Of course software like Browsers can be attacked. Also, the days of sharing 3.5" floppy disks with your classmates are kind of over. So what would you say are the security threats to Linux/Mac machines nowadays, and how does it compare to Windows?
The fool hath said in his heart, There is a God. They are corrupt, they have done abominable works, there is none that doeth good.
Psalm 14, KJV revised edition