The law expressly forbids gathering crowds to disturb public order.
Tips
register
Strongly negative legal register. Almost always paired with bad acts: 聚众斗殴 (group brawling), 聚众闹事 (mob disturbance), 聚众淫乱 (group obscenity). All are formal Criminal Law charges in China.
mistakes
Not a neutral 'gather'. For a positive crowd-gathering use 聚集 jùjí or 集合 jíhé. 聚众 implies organizing or instigating people for an illegal/disruptive purpose.
