Kangaroo court

The Concordia Intelligencer says "several loafers were lynched in Natchez last week upon various charges instituted by the Kangaroo court.[…]" What is a Kangaroo court, neighbor?

On the evening succeeding the election, a meeting was gotten up some what in imitation of a "Kangaroo Court," for the purpose of trying three individuals, […]

One of the principal amusements of the bar during these sessions of the court, is to assemble in some sufficiently capacious room, and after indulging in all the boyish games that occur to them, to institute mock proceedings against some one of their number, for some ridiculous, imaginary offence. […] By an unanimous vote, Judge G.—the fattest and funniest of the assembly—was elected to the bench, and the "Mestang" [i.e., mustang] or "Kangaroo Court" regularly organized.

Sol Tuttle interposed; "Don't you let nobody hev any witnesses i[n] this kangaroo court?"

He [Judge Murray] endeavors to place me in the position of having assailed him, by describing the courts held by him as Kangaroo courts, and imputes to me a settled purpose to alienate all social and friendly relations, between the bench, bar, officers of the court, and all others, who come in direct contact with the courts. Now, all this is simply untrue, as well as ridiculous.

[A]bout twenty prisoners were confined in the city prison at the time and were all more or less drunk on white line (alcohol) furnished through the window by outside parties; […] two kangaroo courts were held the day on which Varnoff was convicted of violating the prison rules, was fined 50 cents each time and searched by officers of the court.

They take him off to face their kangaroo court in the cellar of a deserted brewery.

[W]here police take matters in their own hands, seize victims, beat and pound them until they confess, there cannot be the slightest doubt that the police have deprived the victim of a right under the Constitution. It is the right of the accused to be tried by a legally constituted court, not by a kangaroo court.

A military commission trial falling short of the full UCMJ standard is all but certain to be pejoratively judged as a "kangaroo court" in the court of public opinion.