This is a new type of business, called "research company" . What they are 'researching' is whether or not your number is private, or in other words,a personal, civilian number. They will know by you answering. Even worse, you including your name on their DNC,or DO NOT CALL list. Thats how they confirm you are a person, not business,(thats a diff list). Once confirmed, your info belongs to them (remember, by calling someone back, or by adding ur info to some DNC , you've now legally shared your info with them) they can legally sell your info to other call centers,& research centers. JUST DON'T ANSWER, DON'T PRESS IGNORED SO IT GOES TO YOUR VM, PRESS SILENCE & LET IT RING. They will take you of the regular list. When they call back a month later, DO IT AGAIN! That most likely will do the trick. Trust me,I know first hand how this works. Don't be stupid people, stop VOLUNTEERING YOUR INFO BY CALLING BACK OR ADDING IT TO THE DNC.