It is very common that we receive phone calls from unwanted persons. Most of them call for marketing purpose or sometimes they may be prank calls also. In those cases, we will be able to notice the number of the caller, but we cannot find out who exactly is calling us.
It becomes most important for us to know who is calling us. We cannot complain against them everytime as they may be our friend who just called for fun. In such cases we should take the assistance of phone number registry which has a database of all phone numbers. We should first reverse lookup the phone number with directories. One such cell phone number directory is available at cellphoneregistry.org.
Cellphoneregistry is the largest mobile phone number database in US and Canada providing instant mobile searches. It is most frequently updated too.
So, if someone annoys you on phone, check out this directory to find out who it is and you can start playing with them 
sounds like quite a useful service. What I don’t like about receiving prank calls is the feeling of helplessness that goes with it. Since you don’t know who made the call, you don’t know how to respond, and there’s no way to punish the prank caller. With a service like this, it looks like the tables are turning.