We all get pesky robocalls and each one presents a problem. If we do not recognize the number, should we answer? Ignore? Block the number?
Apparently, the answer is that none of these actions make much of a difference.
To better understand how these unwanted callers operate, we monitored every phone call received to over 66,000 phone lines in our telephone security lab, the Robocall Observatory at North Carolina State University. We received 1.48 million unsolicited phone calls over the course of the study. Some of these calls we answered, while others we let ring. Contrary to popular wisdom, we found that answering calls makes no difference in the number of robocalls received by a phone number. The weekly volume of robocalls remained constant throughout the study.
Blocking the number does not help much because most of those numbers are not from the real caller.
Using these techniques, we learned that more than 80% of calls from an average robocalling campaign use fake or short-lived phone numbers to place their unwanted calls. Using these phone numbers, perpetrators deceive their victims and make it much more difficult to identify and prosecute unlawful robocallers.
I never answer calls from an unknown number that does not leave a message. But I once got a call that my caller ID identified as from a friend, giving both his name and his actual number. I of course picked it up but it turned out to be another robocall. It must be that they had just happened to select a sender number that was in my address book.
This is a nuisance that will not go away.