So basically your company has an enormous number of highly secured steel doors, but only three walls?
Funny, but (fortunately) not the best analogy. I'd say it's more like having a screen door inside the bank vault. We have a lot (and I mean a lot) of precautions in place, some of which I didn't even know existed until I started working there. I actually think the easiest way to get past them all would be to physically force your way into one of our buildings and remove it that way. Come to think of it, I can't think of a single instance of malware infection since I started working there.
Another funny tidbit, though... There is an option to install Firefox on our workstations, but most users are not allowed. It's just what the software says because it doesn't know how to say anything else, but I always thought that was funny, too.