Judith Miller has been guilty of some extremely shoddy journalism during her career.

Even so, the decision by a federal judge to jail Miller for refusing to testify in an investigation into the unmasking of a CIA agent is deeply disturbing.

It's a dark day for press freedom when an American journalist is jailed for protecting confidential sources.

It also violates the Principles on Freedom of Expression drawn up by the Inter-American Commission on Human Rights -- of which the US is a member -- which states that "Every social communicator has the right to keep his/her source of information, notes, personal and professional archives confidential."

But worst of all the judge's ruling makes a martyr out of a thoroughly unreliable journalist.