From legal-dictionary.com, kangaroo court is defined as such:
[Slang of U.S. origin.] An unfair, biased, or hasty judicial proceeding that ends in a harsh punishment; an unauthorized trial conducted by individuals who have taken the law into their own hands, such as those put on by vigilantes or prison inmates; a proceeding and its leaders who are considered sham, corrupt, and without regard for the law.
What are some other terms or phrases that could be synonyms of 'kangaroo court'? I was thinking that in Gulliver's Travels there were parts where Gulliver found himself at the mercy of such "kangaroo courts" and knowing how Swift describes things with such phrases, I thought I could find a synonym of it but haven't been able to.