In the aftermath of World War III, Earth endured a lawless period known as the post-atomic horror, whose courts Q recreated in 2364 to put humanity on trial.
The post-atomic horror describes the chaotic years after World War III, when governments had collapsed and much of humanity lived under harsh improvised authorities. Courts of the period were notorious for summary judgments, and soldiers were kept under control with narcotics.
In 2364 Q staged a trial of humanity in a recreation of such a court, set in 2079. Q presided as judge and accused the crew of the Enterprise-D of humanity's crimes, while Picard insisted that they be judged by their own actions rather than by the record of their ancestors.