Telemarketing Blocker is free Caller ID screen software that retrieves caller s telephone number using your voice modem (you must have subscribed Caller ID feature from your TeleCom. and your modem supports Caller ID in your local state). It can block your unwanted calls from telemarketers, surveys, charities, prank calls or automated dialers. You may setup your private block list (for prank calls) or import a public (for telemarketing calls) block list from our user sharing block list. Also it works in two modes: Mode1 (Transparent) or Mode2 (Replace Ringer).