Why aren't some USA numbers in whitepages?

[M]

I want to find a name living in California, but can't find. I want her cell no. The internet wasn't w/ the result, said there are X ppl in USA & even none of them I want (or in California). How can someone help & why?

[thatdude]

Usually some people chose to not have their name and number listed in the white pages.

[Doug R]

Most folks don't want their numbers available to people they don't know. Even with the " National Do Not Call List " unwanted calls still occasionally come through. If a person I know wants to really contact me, they can try on facebook or other social media. IF I choose to respond, so be it.
I treat others with the same respect.

[mikedotcom]

I pay to keep mine out