The minute you answer your phone, you become a victim because that caller will hound you for months then sell your number as 'live', and the calls won't stop even if you don't fall for the scam-game.
We do not answer any calls we don't recognize. If they don't leave a message, they never hear from us. If it's important, we'll call back. All friends, family, and business associates are in our call log under the name of caller. Anyone else gets a message to leave a message. :) If it's not important enough to leave a message and an identification of caller, it's not important enough to return the call.
IF a call-from number appears twice with no message, it gets blocked.