Fifth Amendment capitalist
n. An American executive who invokes the Fifth Amendment of the United States Constitution to avoid giving testimony regarding possible wrongdoing at his or her company.
We haven't reached the stage yet where the alleged Enron culprits are being called "Fifth Amendment capitalists," but it's probably fair to suggest that those who have used and will be using the legal protection will likewise be assumed to be guilty in doing so.
—Jules Witcover, “Enron's suits bring 'Fifth' back in vogue,” The Baltimore Sun, February 13, 2002
2002 (earliest)
Senator Joseph McCarthy invented the term 'Fifth Amendment Communists.' Soon, we may have a new class: Fifth Amendment Capitalists.
—Noah Adams, “Enron story likely to get a lot bigger before it goes away,” National Public Radio, February 04, 2002
The U.S. Constitution's Fifth Amendment is usually invoked by a person who does not want to testify before a court of law or other body because the testimony would somehow incriminate that person. Here's what "the Fifth" (as it's often called) has to say (italics mine):
No person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a Grand Jury, except in cases arising in the land or naval forces, or in the Militia, when in actual service in time of War or public danger; nor shall any person be subject for the same offence to be twice put in jeopardy of life or limb; nor shall be compelled in any criminal case to be a witness against himself, nor be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation.
As the earliest citation mentions, this phrase is a play on the term Fifth Amendment Communist that was popular when Joseph McCarthy was hunting communist witches in the 1950s.