Beijing has summoned the United States’ top envoy in Hong Kong to protest against the consulate’s move to issue an alert to American citizens about legal changes in the city that punish those who withhold smartphone passwords from police during national security investigations. The foreign ministry’s office in Hong Kong revealed on Saturday that its commissioner, Cui Jianchun, had summoned and lodged “solemn representations” with US Consul General Julie Eadeh the day before in response to the...