Yeah well I don't answer callers I don't recognize. For peace of mind in your life don't open the door unless you know who it is and treat your phone likewise, do not answer unless you know who it is.
Just got a call from 415.742.8805. No one there. Blocked now. The person prior to me (I got his phone number; how lucky of me) did not pay his bills. Now I have the luxury of having to field his bill collector's calls.