Said on the floor and protected by the "speech and debate" clause. Precisely why Massie dangled the carrot of these names but wouldn't release them.

Speech and Debate Clause:

It provides absolute immunity to members of Congress (Senators and Representatives) for their legislative activities. This means they cannot be sued in civil court, prosecuted criminally, or otherwise "questioned" (e.g., forced to testify or have evidence used against them) in any other forum — such as by the executive branch, courts, or private parties — for things they say or do as part of their official legislative duties.