The military trials planned for prisoners at Guantánamo Bay, Cuba, have been referred to as occurring in “a star chamber” or “a kangaroo court.” Without understanding the legitimacy of the label (or of the proceedings), that designation could be just or unjust.
The original “Court of Star Chamber” was an actual room set up in fourteenth century London in which the king’s councilors would adjudicate outside of more formal common law. (The ceiling was said to be decorated with stars, hence the name.) But under James I and especially Charles I, the court was used as an instrument of power to mete out harsh, arbitrary judgments in secret, often with the help of confessions exacted through torture. The “Star-chamber” (as rendered by the Oxford English Dictionary) was abolished in the mid-seventeenth century.
Since then, “Star Chamber” (as rendered by Webster’s New World and American Heritage) has been used to describe everything from a trial held behind closed doors to a lynching. Although the term is often used to describe a politically motivated court, or one that is secret or unfair, careful writers should use “star-chamber” (Merriam-Webster) only to describe a formal court proceeding conducted in secrecy, with a foregone conclusion and a frisson of nastiness. (Or, if you like, an Inquisition.)
Recently, some writers have been equating “star chamber” (most frequent, though nonconforming spelling) and “kangaroo court.” They’re not exactly the same thing.
A “kangaroo court” is, by definition, an unofficial court where the “judges” are self-appointed, usually vigilantes. It’s supposed to be quite public, for its propaganda value. The judges in a “Star chamber” (might as well complete the spelling circuit), by comparison, are real judges, behaving badly.
Many people think the term “kangaroo court” originated in Australia—denoting a trial held where only the kangaroos could witness it. But the phrase is an American invention; it doesn’t even appear in the Australian Oxford Dictionary.
“Kangaroo courts” originated in the lawless West—hence the companion term, “frontier justice.” According to WNW, a “kangaroo court” is “said to be so named because its justice progresses by leaps and bounds.” It has also come to mean a mockery of justice within the judicial system, but—again—very publicly, for propaganda purposes.
So unless someone believes that the judges trying Guantánamo prisoners are vigilantes, and unless the trials are very public, those trials are not taking place in a “kangaroo court.” As to what they should be called, perhaps history will render the final judgment.