I just found out that using a reverse phone number service (like the one that http://www.mobilenumbr.com offers) I can actually get information about the number. For example if I received a call from 423-201-0011 I will query it's details using www.mobilenumbr.com then I can have the name of the owner, the location, the email address and even the social network accounts if there's any.

1. SPAM CALLS

2. ABOUT SPAM CALLS
 Unwanted calls and text messages can come
in the form of either SPAM or harassment.
 SPAM is most common and is more easily
dealt with but harassing calls are more
serious and sometimes require more radical
action.

3. WHAT TO DO WITH SPAM CALLS?
 You may use a reverse phone number
lookup site to get information about the
number. By using services from
http://www.mobilenumbr.com, the most
reputable reverse phone number lookup, you
can locate the origin of the call, the name of
the owner and even report the number as
spam.