“We must maintain order for Hong Kong,” police shouted at protesters through loudhailers. “This is an illegal assembly. We will arrest or disperse you if you don’t leave now.” Many demonstrators used surgical masks to cover their faces, after reports that Beijing had drawn up a “blacklist” of protesters who were being banned from travelling to Mainland China. On November 15, three prominent student leaders were prevented from boarding a plane to Beijing where they had hoped to air their grievances to senior Communist Party leaders.