It's called reverse cell phone directory.
These type of directories allow the general public to get access to cell phone number listings.
You type a number into one of the directories on the Internet, and you instantly get access to the name, address, date of birth, gender, occupation and phone provider of the cell phone owner.
These types of services can be used in a good way.
If you're receiving prank calls on a daily basis you can find out who the prankster is.
If you misplaced the address of a certain indvidual but you have the cell phone number you can retrieve their address.
If you suspect your partner is cheating on you, because they always seem to be taking calls at weird hours into the night you can find out if they are.
These are all popular reasons for someone wanting to obtain information on a certain cell phone owner.
So where can you find these directories? You can do a Google search to find them.
There are atleast 10 of them on the Internet.
I've used the majority of them and they all provided me with good results.
You do have to pay these directories a small fee, which is understandable.
As they have to hire staff to maintain their massive databases.
You can perform a single search in a directory for as little as $10.
Or you can choose to get a lifetime membership on some of them, and the lifetime membership comes with an unlimited amount of searches.