I don't really understand the motivation trying to keep one's phone number or address secret.
I don't really understand the motivation trying to keep one's phone number or address secret.
The white pages never told me who was friends with whom. Or what everybody's sexual preferences were. Or any other data except their name and phone number.
One FB notices that you exist, they build a profile on you that includes much more than these two pieces of info. OP was trying to avoid being "noticed" by FB in the first place, to prevent the profile being assembled.
Law enforcement, most libraries and other phone companies always had access to public printed reverse number phone books in the late 1980-1990's.
Random people/companies calling you at home, harassment, generally people on the internet being less than civil especially if you are a woman.