we're following multiple breaking stories including new subpoenas and demands for documents in the rapidly-expanding impeachment investigation of president trump. as we're learning attorneys for the house intelligence committee are discussing what is described as extreme measures to protect the identity of the original whistle-blower if that person does testify. let's get insight from our political and legal experts. jeffrey toobin, do you think the extreme measures to protect the whistle-blower are necessary. >> i sure do. and let me give you three words why. christine blasey ford. think about that woman who was -- you could say the whistle-blower in the brett kavanaugh confirmation hearings whose life was turned upside down, who was harassed, who has at least for many months couldn't live in her house and that is minor league baseball compared to the world cease of an impeachment situation.