A museum dedicated to China’s court system is marking its opening by displaying items from the politically sensitive trials of two disgraced former leaders. Some in China’s boisterous online world, however, don't see it as a matter of justice being served.

Visitors to the new China Court Museum in central Beijing can see a handcuff, two gavels and the verdicts against former security czar Zhou Yongkang and former Chongqing Communist Party boss Bo Xilai from their separate, unrelated trials. The verdicts, displayed in a glass...