Think about this. Let's say I trust my friends (so when my friends sign John Doe is John Doe, it's really him). It's a big deal (not every friend is so security conscious, maybe he met this guy on facebook and looks so real), but would I trust someone because of a friends-friend's recommendation?
I know which friends are naive. But which friend's-friend's-friend is naive?
And those are the only web-of-trust connection I have with him? Can I trust him? Can I not? How do I tell?