Maybe you have to press a DTMF digit first, something the robocalls wouldn't know how to do? (and have no incentive doing, as so far nobody is using this to blo

Maybe you have to press a DTMF digit first, something the robocalls wouldn't know how to do? (and have no incentive doing, as so far nobody is using this to block robocalls; I'd expect them to catch on if this kind of "firewall" starts being in widespread use)