Any IT person worth their salt knows that OS X is not based on Linux.
Additionally, any IT person worth their salt knows that a system is only as strong as their user is smart, which generally means that it's like a Corvette with the top down, windows unlocked, and a big sign saying "There's a million dollars sitting in the back seat."
EDIT -
A trojan horse is an attack that pretends to be something else. Let's see if I can find an example.. aha! The Trojan Horse! A gift from the Trojans, but in reality the horse was full of soldiers. Trojans spread by social engineering, through stunts like "this site requires JavaScript", "please enter your password", etc. Saying "please enter your password" is like going to a restaurant and being asked for your social security number and your billing address when you need to use a credit card. Maybe you'd tell them, but I'd say "Hold my drivers license when I go to the bank to get cash, then to the police station."