Why are you posting this here?  This is a web site for determining who is calling from unknown numbers.  What do you mean by "this person is exploiting child porn?"  Has this number called you?  If you know who this is then you should be reporting it to the police.  If you are just posting nasty comments, save it for facebook.  Posting something like this about someone whose identity might be determined from the phone number could be slanderous or libelous if it is untrue or unfounded.