Where does "open and transparent" get you?

President Trump vents after meeting with Schumer and Pelosi. One of the things he mentions is Pen Registers. A commenter at the Conservative Treehouse explains,

A Pen Register is….the last step in the process of getting a Title 3 Warrant to “TAP” a phone line. It is only used to get that phone tap warrant and nothing else. So, without saying…Mueller told us that he “TAPPED” 500 PHONE NUMBERS in real time belonging to President Trump, his family and his associates. Mueller did not want us to know that!