But how many people have added their full address and phone number to their Facebook profiles anyway? I would bet that the majority of people have their city/town set and not their full address and won't have specified their phone number at all.
However, this really could be quite useful if used legitimately, i.e. Facebook commerce, having shipping address available; location aware apps etc.
Anecdotally, something like 30% of my friends list (not particularly tech-savvy skewed) probably share their phone numbers.
It's also one of the most useful features of the whole site, if I'm out somewhere and realise I suddenly need to call someone whose number I can grab from Facebook.
However, this really could be quite useful if used legitimately, i.e. Facebook commerce, having shipping address available; location aware apps etc.