called my mother claiming ro be Medicare or Medicaid saying they needed to update information..than said thanks your meter is on its way..the caller id said 24 hour tow and locksmith. ...she did not check caller id before picking up phone...this is a scam  

It's use by marketers who pass them around for multiple scams.  In my own experience it was used by a Boggus "extended warranty" deal and more recently some sort of unscrupulous diabetes supplies by mail scam.   I welcome all details.    I'm writing an article about this for the New Yorker Magazine.   Thank you.