> That's only really true for shell users who are both knowledgeable and determined to break security.
1. For users that are not determined to break security, a simple post-it "please do not access the files under /home/me/pr0n" suffices (this is an exaggeration, if it's not totally clear...).
2. As I mentioned in my other comments below, mistakes made by unknowledgeable shell users can eventually lead to total box compromise.