Where do you actually get free white pages on the web? There is one service I have used that will give me additional information such as satellite maps of the location, known neighbors and relatives, other numbers by the owner and in one particular case, that I found quite beneficial, was when they also gave me a person's address history.
You may be wondering why you need a reverse look up of phone number. It is also reported that free directory services are more likely to out-of-date data. Now you don't need a pile of telephone directories using up lots of space in your garage when you can access the information by a click from your mouse.
There is therefore a high probability that you will not find what you are looking for. If at all, you are unable to find the name of a person related to a particular number then in all probability, it is an unlisted cell phone number. Who knows, the caller might be a neighbor or someone just a few blocks away from your place and if you and the authorities are aware of it, you will get the necessary protection.
Take time now to use reverse services to get the information you deserve. Most of the services will offer you money back guarantees.