My Experience
Anti-Malicious security measures are almost always cumbersome, prompting people to work around them in order to get their jobs done.
I have found that it is much better to make security usable and transparent (like not being able to even see directories for which you aren't authorized, as opposed to directories with big padlock icons on them).
That seems to be emerging as SOP these days.
Make security transparent, unobtrusive and usable. Make it easier to follow security protocol than to go around it.
That will go a long ways towards reducing accidental breaches.