Why can't I see a friend's friends on facebook?

[Mary]

I have one friend, and when I click on his profile, it only lists our mutual friends. Why can't I see his entire list of friends? This person is the only one where this is the case. What gives?
What does that mean? That means he has set them so I specifically can't see the friends on his list?
So you can set privacy settings so that certain people can't see your list? Or do you have to do this for your entire list?

[Dylan]

His security settings are different.

[Shannon]

Some people set their privacy settings so you cant.

[Shandy]

It's his Privacy Settings

[Charles H]

In your security settings, you control who gets what information. You can allow your profile to be public, private, or available to friends only and if your profile can be viewed by a friend of a friend. Mine is friends only and my statuses and other posts are friends only. Nobody needs to see anything I don't want them to see, and I can control who is my friend, and even then, who can see what.