We have all experienced telephone calls where you pick up the phone and there is no one on the other end of the line.  This is a scam, but how does it work and how are you harmed?  With computers that can be programmed to make massive amounts of telephone calls,  scammers will often first test their lists of telephone numbers by making these calls to determine which telephone numbers are valid numbers for them to call back later with automated robocalls such as from the infamous Rachel from Card Services  by which they will attempt to either sell you something worthless or gather information from you that can be used to make you a victim of identity theft.

In another version of this scam,  people with Caller ID are often tempted into calling back the number to see who called them, thinking that the call was legitimate.  Instead, unwittingly they make an expensive premium service call to an adult entertainment service that charge as much as $20 for the first minute.  Many of these calls originate in the Caribbean Islands from area codes such as 268, 284,809, 473,876 or 649.

TIPS

It often is a good idea not to answer the phone if you have Caller ID and you do not recognize the number calling you.  If it is legitimate, they will generally leave a message.  In any event, if you do answer the phone and there is no one on the other end of the line, do not call the number back.  The chances of your getting assessed charges for a premium phone call are too great.