One of the arguments against adding a bill of rights to the Constitution was that such a list might imply those were the only rights the people had. Therefore, when James Madison introduced the Bill of Rights in Congress, he included a provision protecting rights “retained by the people,” but not written down in the Constitution. These unenumerated rights referred to in the Ninth Amendment have proven to be very controversial. Libertarians believe that the Ninth Amendment includes certain fundamental rights, such as privacy, that are so important they must be protected by judges, whether or not they are specifically listed in the Constitution. Advocates of judicial restraint argue that such interpretations of the Ninth Amendment give judges too much discretion, and that it is the job of state legislatures and the people themselves to protect unenumerated rights.