Im curious, is there a site (free or not) that I can search for someone using a bit of personal info (age, social security #, etc..)? I cant really say who and why, but its not for anything illegal.
If you know their phone number (with area code), just type it in at Google and it will list where they live (provided they haven't requested to be removed from the directory).
Obviously, law enforcement agencies, financial institutions, credit agencies, etc. have ways of doing what you want to do. But these programs and data are not accessible to the general public.