Why can't I see mutual friends on facebook?

[Amanda]

I think this guy is stalking me and I know his name and it says we actually have one mutual friend on facebook but when I found him and click their facebook it won't show who that mutual friend is. Usually if I am not friends with someone it will still at least let me know who our mutual friend is. In this instance when I do the search it says 1 mutual friend but doesn't say who and furthermore when I click their profile it won't say who. I just want to know which one of my friends might know this person so I can ask them and figure out if this guy is in any way threatening or not.

[Daniel]

If you Cant See that 1 Mutual Friends that Means the 1 Mutual Friend is Either Deactivated or He or She May Have Blocked You