The EveryCaller website allows you to look up unknown callers and, if you want, block calls and text messages...
EveryCaller is a free service to help consumers identify unknown callers and stop unwanted telephone calls. Most American's receive some form of unwanted telephone call on a regular basis, telemarketing, fraud and debt collectors. This site provides a forum for users to find out who's calling and to help put a stop to those calls.
To find out who called just type in the telephone number that showed up on your caller ID in the search box and information about who possibly could be calling from that number will be displayed, including a list of user comments displayed which contain information about the person or company calling from that number. You can leave your comment if you have unique information to add and make available to others. Download their mobile app Call Control on Google Play App Store for $7.99.
According to ScamAdvisor this site is rated: High Trust Rating. This Site Looks Safe To use.
For complete details on this site see the letter to the Federal Communications Commission HERE.
It is also recommended you register your phone number on the Federal government's Do Not Call Registry. For whatever good is might do, you can also file a complaint on the same site.
Additional Sites of Interest:
Forbes Magazine article,Don't Return Calls From These Area Codes -- It's A Scam!
US Government - Common Scams and Frauds
Federal Communications Commission - One Ring Wireless Phone Scam - Some wireless consumers are receiving calls from phone numbers with three-digit area codes that appear to be domestic, but are actually associated with international pay-per-call phone numbers.
These calls often disconnect after one ring, not giving the consumer time to answer the call and tempting them to return the call. If you receive a call like this and do not recognize the number of the incoming call, do not return the call.
If you return the phone call, you may be connected to an international hotline than can charge a fee just for connecting, along with significant per-minute fees if they can keep you on the phone. These charges may show up on your bill as premium services.