I disagree with the walking a thin bar analogy.

   The problem with security is that if it's open it's really open. I
   think it's better to compare the security with the skin. The more skin
   you hide the less easily it'll get poked through, but if you miss some
   spots you can still get all the blood unless you have something to keep
   it in.

   I suppose an analogy to the human body is the server is more
   explanatory.

   So I tend to want to ask "are there any holes anywhere" or "where is my
   armor the thinnest?". And I've found that "other person software" is
   the mayor hole in everything. Honestly, it's hardly ever the code you
   write yourself that's the problem. Also because hard lifting is done
   for you, but the point remains that there's something about big-kernels
   and systems packed with bulging software packages are just.. It's hell.
   So much skin. So hard to check.