Why can't i google search friends A and B, who are on each other's facebook friends list?

[berrie]

However, when i google searched friend A and C who are on each other's facebook friends list, it does show me the result. That means, it does appear that friend A and C are facebook friends. So, why don't friends A and B show the same positive result since both are friends on their own facebook list?
Both A and B have public search listing, because I could find their individual facebook profile on google search. I could google search A and C as well as B and D. But why can't I google search A and B to show up as facebook friends of each other?

[how knows!!!]

Well, check out the pravicy setting and you'll know why!!!!!!!!!